Green Science 10 Final PDF (2076)

Gas jar

Mixture of NH4Cl Stand
and Ca(OH)2 CaO

Hard glass test tube

Bunsen burner

5. What happens when (write with a balanced chemical equation for each):
a. Carbon dioxide is passed through lime water for a while.
b. Carbon dioxide is passed through lime water for a long time .
c. Carbon dioxide reacts with potassium hydroxide.
d. A burning magnesium ribbon is inserted in the gas jar containing carbon dioxide gas.
e. Ammonia reacts with conc. hydrochloric acid.
f. Ammonia is heated with carbon dioxide at about 1500°C.

6. Give reason:
a. Carbon dioxide is collected by upward displacement air.
b. Carbon dioxide cannot be collected in the gas jar by passing it through water.
c. Moist blue litmus is used to test carbon dioxide gas.
d. Ammonia is passed through lime tower.
e. Ammonia gas is collected by downward displacement of air.
f. Ammonia gas cannot be collected in the gas jar by passing it through water.

7. How is urea prepared ? Write with a balanced chemical equation.

8. What is Haber's process? Write down the conditions required for Haber's process.

GREEN Science (Chemistry) Book-10 201

Grid-based Exercise 2

Group ‘A’ (Knowledge Type Questions) (1 Mark Each)

1. Name two chemicals which are required to prepare carbon dioxide gas in laboratory.

2. Which gas is obtained by reacting slaked lime and ammonium chloride?

3. Write down the molecular formula and molecular weight of carbon dioxide.

4. What is the percentage of carbon dioxide in atmosphere ? (Ans: 0.03%)

5. Write the molecular formula and molecular weight of ammonia.

6. Write any two physical properties of carbon dioxide gas.

7. What is Haber’s process?

8. Which gas is obtained by reacting limestone and dilute hydrochloric acid?

9. Which gas is used to take out blue print?

10. What happens if ammonia gas is passed into water containing a few drops of
phenolphthalein solution ?

11. What happens when carbon dioxide gas is cooled to -78°C ?

12. What is promoter? Give an example of it.

13. Which gas is produced in the chemical reaction of dilute hydrochloric acid and marble
pieces ?

14. What is dry ice?

15. Write any two physical properties of ammonia gas.

Group ‘B’ (Understanding Type Questions) (2 Marks Each)

16. It is dangerous to clean well remaining closed for a long time, why?

17. Write any two differences between carbon dioxide and ammonia gas.

18. Why is carbon dioxide gas used in fire extinguisher?

19. Ammonia gas cannot be collected in an erect gas jar, why?

20. Lime water turns milky when carbon dioxide gas is passed through it, why ?

21. Carbon dioxide gas can be tested with the help of moist blue litmus paper, why?

22. Which gas is collected in the gas jar laboratory by downward displacement of air ?
Why ?

23. Carbon dioxide gas is important for green plants,why?

24. A moist red litmus paper is used for testing ammonia gas, why?

25. Carbon dioxide gas is not collected over water, why?

Group ’C’ (Application Type Questions) (3 Marks Each)

26. Draw a neat and labelled figure showing the laboratory preparation of carbon dioxide
gas with balanced chemical equation.

27. How is carbon dioxide gas manufactured in industries ? Write with chemical equation.

28. Write any three utilities of carbon dioxide gas.

202 GREEN Science (Chemistry) Book-10

29. How is ammonia gas manufactured in industries ? Explain.

30. Write any three utilities of ammonia gas.

31. Which gas is obtained by heating the mixture of Ammonium chloride and Calcium
hydroxide? What happens when glass rod dipped in hydrochloric acid is brought in
contact with this gas? Also, write the chemical equation.

32. Draw a neat and labelled figure showing laboratory preparation of ammonia gas with
balanced chemical equation.

Group ‘D’ (Higher Abilities Type Questions) (4 Marks Each)

33. Answer the questions after observing the given figure: Delivery tube

i. Which gas is being collected Dil. hydrochloric acid

in the gas jar? Thistle funnel

ii. Write an equation for the Gas jar
chemical reaction of the gas
preparation. Pieces of CaCO3

iii. This gas cannot be collected
by downward displacement
of water, why?

iv. What happens when a burning magnesium ribbon is inserted into the jar
containing this gas ?

34. Ammonia gas can be prepared by heating two solid substances in laboratory. Answer

the following questions: 2+2

i. Write down the name of two Gas jar
solid substances are used in it
with their molecular formulae. Mixture of NH4Cl Stand
and Ca(OH)2

ii. Draw a well labelled diagram Hard glass test tube CaO
of the laboratory preparation Bunsen burner
of this gas.

35. Answer the following questions with the help of the given figure. 1 +2+1

i. Which gas preparation does the given figure show ? Gas jar
Gas jar
ii. Write down a balanced chemical equation
involved in it.

iii. What substance will be produced when Gas

the above gas reacts with water ? Write the Marble

chemical equation.

GREEN Science (Chemistry) Book-10 203

UNIT Metals

11

Weighting Distribution Theory : 7 Practical: 1

Before You Begin

Scientists have discovered 118 elements so far. Among them, most
elements are metals. The elements that form electropositive ions
(except hydrogen) and conduct heat and electricity are called metals.
They are very useful for human beings. Metals are being used by
human beings from ancient time. Metals are malleable and ductile.
They are good conductor of heat and electricity. They are shiny and
lustrous. Most metals are hard and exist in solid state. Metals are used
for making construction materials, cooking utensils, automobiles,
ornaments, electric wires, coins, equipment, weapon and so on. In this
unit, we will study some common metals (iron, aluminium, copper,
silver and gold), their occurrence in nature physical properties and
uses in brief.

Learning Objectives Syllabus
After completing the study of this unit, students will be able to:
i. explain the metals (iron, aluminium, copper, silver • Introduction to metals
• Some important metals
and gold) and their occurrence in nature. – Iron
– Aluminium
ii. state physical properties of above given metals. – Copper
– Silver
iii. explain the uses of above given metals – Gold
• Physical properties and uses

of metals

Glossary: A dictionary of scientific/technical terms

metals : electropositive elements which conduct heat and electricity
malleability : the property of a body by virtue of which it can be beaten into a thin sheet
ductility : the property of a body by virtue of which it can be drawn into a long wire
ore : the mineral from which a metal can be extracted for commercial purpose
minerals : those naturally occurring substances that contain metals in more or less

lustrous amount
lustre : having lustre; shining
: the shine from the surface of a mineral

204 GREEN Science (Chemistry) Book-10

Some Important Metals

1. Iron

Iron is an abundant metal found on the earth's crust. In Latin language, iron is called
ferrum. So the symbol of iron is 'Fe'. The atomic number of iron is 26 and its atomic weight
is 56. The electronic configuration of iron is given below:

Shell K L M N
No. of electrons 2 8 14 2
Orbital 1s² 2s² 2p6 3s² 3p6 3d6 4s²

Position of iron in Modern Periodic table

Iron belongs to d-Block, group 8 and 4th period of Modern periodic table. The valency of
iron is 2 or 3.

The outermost s-sub-shell of iron consists of 2 electrons. So the position of iron should
be in group 2 but it is placed in group 8 of the modern periodic table because it is a
transitional metal. The properties of iron differ from those of normal elements. Iron forms
ferrous ion (Fe++) by losing two electrons and ferric ion (Fe+++) by losing three electrons.

Occurrence and Ores of Iron

Iron is found in very less amounts in free state in nature as it is a reactive element. Iron is
found in the from of ores in nature. Very less amount of iron is found in the body of living
beings. It is found in blood in the form of haemoglobin.

The main ores of iron are haematite Do You Know
(Fe2O3), magnetite (Fe3O4), limonite
(Fe2O3.3H2O)iron pyrite (FeS2) and Ores are the minerals from which metals can
siderite (Fe CO3). Haematite is the be extracted in a large amount for commercial
principal ore of iron. It consists of purpose, e.g. haematite, bauxite, etc.

about 72.5% iron. Generally, iron is

extracted from haematite ore as it is abundant on the earth's crust.

Fig.

11.1 Magnetite ore Iron pyrite ore Siderite ore
Haematite ore

Physical properties of iron
1. Pure iron is an ash coloured grey white metal.

2. It is good conductor of heat and electricity.

GREEN Science (Chemistry) Book-10 205

3. It is malleable and ductile.
4. Its specific gravity is 7.86.
5. Iron melts at 1500° C and boils at 2500° C.
6. Iron loses magnetic properties when heated above 770° C.

Uses of Iron
1. Iron is used for manufacturing building materials like rods, pipes, wires and

machinery parts.
2. It is used for making parts of vehicles, railway tracks, etc.
3. It is used for making nails, nuts and bolts and household utensils.
4. It is used for making cooking utensils and agricultural tools.
5. It is used for making weapons and different types of tools.
6. It is used in various chemical reactions as a catalyst.
7. It is used to manufacture steel.

Fig.

11.2 Weapon made of iron Cooking utensils made of
iron
Construction of building
using iron rods

2. Aluminium

Aluminium is an abundant metal found on the earth's crust. Its symbol is Al. Its atomic
number is 13 and atomic weight is 27. The electronic configuration of aluminium is given
below:

Shell K L M
No. of electrons 2 8 3
Orbitals 1s² 2s² 2p6 3s² 3p1

Position of Aluminium in Modern Periodic Table
The outermost shell of aluminium consists of three electrons. So it is kept in group 13
of modern periodic table. It is kept in p-Block and 3rd period of modern periodic table.

206 GREEN Science (Chemistry) Book-10

Aluminium loses three electrons from the valence shell and forms aluminium ion (Al+++).
The valency of aluminium in 3.

Occurrence and ores of aluminium

Aluminium is a highly reactive metal. So it is not found in free state in nature. It is found
in the form of compounds and ores in nature.

The main ores of aluminium are:

i. Bauxite (Al2 O3. 2H2O)
ii. Feldspar (KAlSi3O8)
iii. Cryolite (Na3AlF6)
iv. Kaolin (Al2Si2O7.2H2O)
Bauxite is the principal ore of aluminium. Therefore, aluminium is generally extracted
from this ore.

Fig.

11.3 Cryolite Feldspar
Bauxite

Physical properties of aluminium
1. Aluminium is a shiny and silvery-white colured metal.
2. It is good conductor of heat and electricity.
3. It is highly malleable and ductile.
4. Its specific gravity is 2.7.

5. It melts at about 660°C and boils at about 1800°C.

6. It is very light and strong metal.

Used of Aluminium
1. Aluminium is used for making cooking utensils due to its light weight and rust free

nature.
2. It is used for making bodies and parts of aeroplane, ship, car, motorcycle, etc.
3. It is used for making electric wires, photo frames, etc.
4. It is used for making materials for construction like windows, doors, roofs, etc.
5. It is used for making silver paint by mixing its powder with oil.

GREEN Science (Chemistry) Book-10 207

6. It is used for making aluminium foil for packaging medicines, chocolates, etc. and
packing foods.

7. It is used for making coins and alloys.
8. It is used for making overhead electric cables.

Fig.

11.4 Parts of aeroplane made of Aluminium foil
Utensils made of aluminium aluminium

3. Copper

Copper is a reddish-brown shiny metal. Its Latin name is cuprum. So its symbol is Cu.
The atomic number of copper is 29 and its atomic weight is 63.57.

The electronic configuration of copper is given below:

Shell K L M N
No. of electrons 2 8 18 1
Orbital 1s² 2s² 2p6 3s² 3p6 3d10 4s1

Position of copper in modern periodic table

Copper has one electron in its outermost shell. So it is placed in group 11 of the modern
periodic table. It belongs to d-Block and 4th period of the modern periodic table. Its valency
is 1 or 2. It forms cuprous ion (Cu+) by losing one electron and cupric ion (Cu++) by losing
two electrons from the valence shell.

Occurrence and ores

Copper is found in pure as well as in combined state in nature. The main ores of copper
are:

i. Copper pyrite or chalcopyrite (CuFeS2) [Principal ore]
ii. Chalcocite (Cu2S) or copper glance and
iii. Cuprite (Cu2O).
iv. Malachite [Cu(OH)2.CuCO3]
v. Azurite [Cu(OH)2.2CuCO3]
Copper is generally extracted from copper pyrite or chaolcopyrite.

208 GREEN Science (Chemistry) Book-10

Fig. Fig.11.5 Chalcocite ore Cuprite ore
Chalcopyrite ore

Physical properties of Copper
1. Copper is a shiny reddish - brown metal.
2. It is a very good conductor of heat and electricity.
3. It is highly malleable and ductile.
4. Its specific gravity is 8.95.
5. It melts at about 1083°C and boils at about 2350°C.
6. It is soft in nature.

Uses of Copper
1. Copper is used for making household utensils.
2. It is used for making electric wires, electric motor, dynamo and other electric and

electronic appliances.
3. It is used for making steam pipe, vacuum pan and calorimeter.
4. It is used for electroplating
5. It is used for making coins.
6. It is used for making various chemicals, insecticides, germicides and fungicides.
7. It is used in electrotyping.
8. It is used for making alloys like brass, bronze, bell metal, etc.

11.6 Coins of Copper Copper wire
Utensils made of Copper

GREEN Science (Chemistry) Book-10 209

Copper is used in different alloys. Some of the alloys with their composition and uses are
given below:

i. Brass : Brass is the mixture of copper and zinc. It Fig. Fig.
is used to make nutbolts, medals, condenser tube
and household utensils.

11.7

Brass utensil

ii. Bronze: It is the mixture of copper, tin and zinc. It
is used for making coins and household utensils.

11.8

Bronze utensil

iii. German silver: It is the mixture of copper, zinc and Fig.
nickel. It is used for making bells and household
utensils.

11.9

German silver

iv. Bell metal: It is the mixture of copper and tin. It is Fig. Fig.
used for making bells and decorative items.

11.10
Bell metal

v. Gun metal: It is the mixture of copper, tin, zinc and
lead. It is used for making ball bearings and parts
of machines.

11.11
Gun metal wheel

210 GREEN Science (Chemistry) Book-10

4. Silver

Silver is a shiny white metal. Its Latin name is Argentum. So its symbol is Ag. The atomic
number of silver is 47 and atomic weight is 107.9. The electronic configuration of silver is
given below:

Shell K L M N O
No. of electrons 2 8 18 18 1
Orbitals 1s2 2s² 2p6 3s² 3p6 3d10 4s² 4p6 3d10 5s1

Position of Silver in Modern Periodic Table

The outermost shell of silver consists of only one electron. So it is kept in group 11 of
Modern Periodic table. It is placed in d-Blcok and 5th period of modern periodic table. The
valency of silver is 1. It forms silver ion (Ag+) by losing one electron form its valence shell.

Occurrence and Ores of silver

Silver is a less reactive metal. So it is found in free as well as combined state in nature. It
is found in the from of ores. The main ores of silver are argentite or silver glance (Ag2S),
Silver copper glance [(AgCu2)2S], horn silver (Ag Cl), Ruby Silver (Pyrargylite) [Ag2Sb2S3,]
etc. The principal ore of silver is argentite.

Fig.

11.12 Horn silver Silver Copper Glance
Argentite ore

Physical properties of silver
1. Silver is a shiny white metal.
2. It is a very good conductor of heat and electricity.
3. It is highly malleable and ductile.
4. Its specific gravity is 10.5.
5. It melts at about 960° C and boils at about 1955° C.

Uses of silver
1. Silver is used for electroplating.
2. It is used for making coins, decorative items, idols, satues, etc.

GREEN Science (Chemistry) Book-10 211

3. It is used for making medals and ornaments.
4. It is used for shining mirrors.
5. It is used for making ornaments and idols.
6. It is used for making medicines and silver salts.
7. It is used in photography in the form of silver bromide in the negative of a photograph

and x-rays.
8. It is used for filling teeth as silver amalgam.
9. Silver is used for making watch, hearing equipment and battery of calculator.
10. It is used for making solar panel.
11. It is used in water purifiers to prevent algae and bacteria from growing in the filters.
12. Silver nitrate is used as a laboratory reagent.

5. Gold

Gold is a shiny yellow metal. It is a very expensive metal which is used for making
jeweleries and medals. The Latin name of gold is Aurum. So its symbol is Au. The atomic
number of gold is 79 and its atomic weight is 197.2. The electronic configuration of gold
is given below:

Shell K L M N O P
No. of electrons 2 8 18 32 18 1
Orbitals 1s² 2s² 2p6 3s² 3p6 3d10 4s² 4p6 3d104f14 5s2 5p6 5d10 6s1

Position of gold in modern periodic table

The outermost shell of gold atom consists on only one electron. So, it is kept in group 11 of
modern periodic table. Gold belongs to d-block and 6th period of modern periodic table.
Its valency may be 1 or 3. Gold forms aurous ion (Au+) by losing one electron and auric
ion (Au+++) by losing three electrons.

Occurrence of Gold

Gold is a very less reactive or noble metal. So, it is mostly found in free state in nature. Gold
is found in sandy alluvial soil and quartz veins (reef gold). It is also found in sulphide,
oxide, carbonate, sulphate ores. Gold is generally extracted from sandy alluvial soil and
calaverite (Au Te2.).

212 GREEN Science (Chemistry) Book-10

11.13Fig. Fig. Calaverite
Sandy alluvial soil rich in gold

Physical properties of gold

1. Gold is a soft and bright-yellow metal.
2. It is a very good conductor of heat and electricity.
3. It is a very less reactive metal.
4. Its specific gravity is 19.3.
5. It melts at about 1063°C and boils at about 2530°C.

Uses of gold

1. Gold is widely used for making jeweleries, statues and other ornaments.
2. It is used for making medals and idols of god.
3. It is used for making coins.
4. It is used for electroplating.
5. It is used in photography and dentistry.
6. It is used for making anti-inflammatory medicines.
7. It is used for making alloys.
8. It is used for making gold leaf electroscope.
9. It is used for making corrosion resistant electrical connectors in computerized devices.

11.14 Gold coins
Gold ornaments
GREEN Science (Chemistry) Book-10 213

Occurrence of Metals in Nepal

S.No. Metals Ores/sources Occurrence (Districts of Nepal)
1. Chalcopyrite Udaypur, Dhading, Makawanpur,
1. Copper Solukhumbu
2. Copper glance
2. Gold 1. Free gold Rapti
Mustang
2. Sandy alluvial soil Kathmandu
Lalitpur
3. Iron 1. Haematite Bhojpur
2. Magnetite Ramechhap
Tanahun
4. Calcium Limestone Chitwan
Pyuthan
5. Magnesium Magnesite Makawanpur
Dhading
6. Bismuth Bismuth Udaypur
Kathamandu
7. Lead Lead deposit Dolakha
Udaypur
8. Zinc Zinc deposit Makawanpur

9. Cobalt Cobaltite (Bhimphedi)
Lalitupr

Rasuwa (Ganesh Himal)
Lalitupr

Rasuwa (Ganesh Himal)
Gulmi

Palpa

Key Concepts

1. The elements that form electropositive ions (except hydrogen) and conduct heat
and electricity are called metals.

2. Iron is an abundant metal found on the earth's crust. In Latin language, iron is
called ferrum. So the symbol of iron is 'Fe'.

3. Iron belongs to d-Block, group 8 and 4th period of Modern periodic table. The
valency of iron is 2 or 3.

4. The main ores of iron are haematite (Fe2O3), magnetite (Fe3O4), iron pyrite (FeS2)
and siderite (Fe CO3). Haematite is the principal ore of iron.

214 GREEN Science (Chemistry) Book-10

5. Ores are the minerals from which metals can be extracted in a large amount, e.g.
haematite, bauxite, etc.

6. The outermost shell of aluminium consists of three electrons. So it is kept in group
13 of modern periodic table. It is kept in p-Block and 3rd period of modern periodic
table.

7. Aluminium is a light - white colured metal. It is good conductor of heat and
electricity.

8. Aluminium is used for making cooking utensils, bodies and parts of aeroplane,
ship, car, motorcycle, etc. It is also used for making electric wires, photo frames, etc.

9. Copper is a reddish-brown shiny metal. Its Latin name is cuprum. So its symbol is
Cu.

10. Copper is used for making household utensils, electric wires, electric motor,
dynamo and other electric and electronic appliances.

11. Brass is the mixture of copper and zinc. It is used to make nutbolts, medals,
condenser tube and household utensils.

12. Silver is a shiny white metal. Its Latin name is Argentum. So its symbol is Ag.

13. The outermost shell of silver consists of only one electron. So it is kept in group 11 of
Modern Periodic table. It is placed in d-Blcok and 5th period of modern periodic table.

14. Silver is a less reactive metal. So it is found in free as well as combined state in
nature.

15. Gold is a shiny yellow metal. It is a very expensive metal which is used for making
jeweleries and medals.

16. Gold belongs to d-block and 6th period of modern periodic table. Its valency may
be 1 or 3. Gold forms aurous ion (Au+) by losing one electron and auric ion (Au+++)
by losing three electrons.

17. Gold is a very less reactive or noble metal. So, it is mostly found in free state in
nature.

18. Gold is generally extracted from sandy alluvial soil and calaverite (Au Te2.).
19. Gold is widely used for making jeweleries, medals and idols of god.

Sequential General Exercise 1

1. Choose the best answer from the given alternatives.
a. What is the atomic weight of iron?

27 26 56 79

b. Which of the following is the principal ore of aluminium?

Bauxite Feldspar Cuprite Haematite

GREEN Science (Chemistry) Book-10 215

c. Which of the given metals is used to make overhead electric cables?

Iron Copper Gold Aluminium

d. Which of the given metals is found in free state in nature?

Iron Copper Gold Aluminium

e. What is the valency of gold?

1 and 2 2 and 3 1 and 3 2 and 4

2. Answer the following questions.
a. What are metals? Give any three examples.
b. Write any tree properties of metals.
c. What are ores? Give any five examples.
d. Write down any two ores of each iron, aluminium, copper and silver.
e. Why is copper used for making electric wires and cooking utensils?
f. Write down the occurrence of iron and aluminium in brief.

3. Write down any three physical properties any three uses of given metals.

– Iron – Aluminium – Copper

– Silver – Gold

4. Give reason:
a. Iron is used for making cooking utensils.
b. Aluminium is used for making bodies and parts of aeroplane.
c. Gold is found in free state in nature but not iron.
d. Gold is used for making jeweleries.

5. Write any four uses of each copper, silver and gold in our daily life.

6. Where is gold found in nature? Write.

7. Name the metals that can be extracted from each of the given ores.

– Cuprite – Magnetite – Bauxite

– Calaverite – Haematite – Siderite

– Chalcopyrite

8. Write a short note on occurrence of metals in Nepal.

216 GREEN Science (Chemistry) Book-10

Grid-based Exercise 2

Group ’A’ (Knowledge Type Questions) (1 Mark Each)

1. Name any two ores of iron.

2. Write any two physical properties of iron.

3. Name the chief ores of aluminium.

4. Write any two physical properties of copper.

5. Where and in which state is gold found in nature ? Write.

6. Which metal is extracted from magnetite ore ?

7. Name the metal that can be obtained from the given ores:

i. Pyrolite ii. Haematite

8. Write any two physical properties of gold.

9. Name any two ores of copper.

10. Write any two physical properties of silver.

11. What metal is extracted from Bauxite?

12. In which parts of Nepal are given metals found? Write.

i. Magnesium ii. Cobalt

13. Name the metal that can be obtained from the given ores:

i. Azurite ii. Cryolite

14. Write any two physical properties of iron.

15. Name the metals which can be extracted from the ores Argentite and Chalcopyrite.

Group ’B’ (Understanding Type Questions) (2 Marks Each)

16. Iron is used for making cooking utensils, why?

17. Copper is used for making electric wires, why?

18. Write any two differences between iron and aluminium.

19. Why are iron and aluminium used for making cooking utensils?

20. Write a difference between metal and non-metal on the basis of their density. Why is
gold called noble metal ?

21. State any two properties of copper that make it suitable for making pots and pans.

22. The external cover of the aeroplane is made from aluminium instead of iron. Why is
it done ? Give two reasons.

23. Gold is found in pure state in nature but not the iron, why ?

GREEN Science (Chemistry) Book-10 217

24. Why are gold and silver used for making ornaments?

25. Aluminium is a very reactive metal. Then, why is it that the foods in aluminium pots
don’t react with the pots ?

Group ‘C’ (Application Type Questions) (3 Marks Each

26. Write any three uses of iron.
27. Write down three uses ot aluminium.
28. What are the uses of copper ?
29. Write any three uses of silver.
30. Write down the main uses of gold.

Group ‘D’ (Higher Abilities Type Questions) (4 Marks Each)

31. Write down the electronic configuration of iron and mention the position of iron in
the Modern periodic table.

32. Write down the position of silver in periodic table and write a short note on occurrence
and ores of silver.

33. Write down the position of copper in periodic table and write a short note on
occurrence and ores of copper.

34. Arrange aluminium, iron, gold, silver and copper in the increasing order of their
melting points and boiling points.

35. Describe in brief the occurrence of metals in Nepal.

36. Write down the periodic position and electronic configuration (on the basis of sub-
shells) of silver and gold.

218 GREEN Science (Chemistry) Book-10

UNIT Hydrocarbon and Its

12 Compounds

Weighting Distribution Theory : 4 Practical: 1

Before You Begin

A variety of substances are found in our surroundings. Thousands
of compounds exist in nature. These compounds can be divided into
two types, viz. inorganic compounds and organic compounds. The
compounds which are obtained from minerals are called inorganic
compounds, e.g. water (H2O), carbon dioxide (CO2), calcium carbonate
(CaCO3), magnesium carbonate (MgCO3), etc. The compounds
which are obtained from living beings and contain hydrocarbon are
called organic compounds. All compounds of carbon except oxide,
carbonate, bicarbonate and carbide are called organic compounds,
e.g. methane (CH4) propane (C3H8), alcohol, glycerol, ether, etc.
Organic compounds consists of hydrogen and carbon. So, they are
also called hydrocarbons.

Learning Objectives Syllabus
After completing the study of this unit, students will be able to:
i. introduce hydrocarbons and their types. • Introduction to hydrocarbons

ii. state the types of hydrocarbons and define them with • Types of hydrocarbons
examples.
- Saturated hydrocarbons
iii. give general introduction to compounds of
hydrocarbons (methane, alcohol, glycerol, sucrose) - Unsaturated hydrocarbons
and explain their uses.
• Alkanes, alkenes, and alkynes

• Homologous series of
hydrocarbons

• Some hydrocarbons and their
compounds

– Methane, ethane, propane,
butane, alcohol, glycerol, and
glucose

Glossary: A dictionary of scientific/technical terms

hydrocarbons : compounds made of carbon and hydrogen
inorganic : obtained from minerals
organic : obtained from living beings
alcohol : organic compound having hydroxyl (OH) group
glycerol : a sweet organic compound having molecular formula C3H5(OH)3

GREEN Science (Chemistry) Book-10 219

Hydrocarbons

Compounds like methane (CH4), ethane (C2H6), propane (C3H8), etc. made of two
types of elements, i.e. carbon (C) and hydrogen (H). Such types of compounds are
called hydrocarbons. The organic compounds made of carbon and hydrogen are called
hydrocarbons. Methane (CH4), ethane (C2H6), propane (C3H8), propene (C3H6), methyl
alcohol (CH3OH), glycerol [C3H5(OH)3], etc. are some examples of hydrocarbons. Living
beings and petroleum products are the main sources of hydrocarbons.

Fig.

12.1 Ethane Propane
Methane

Types of Hydrocarbons Do You Know

On the basis of types of bond present The full form of IUPAC is International Union
between carbon atoms, hydrocarbons of Pure and Applied Chemistry. This is an
are classified into two types. They are organization which suggests us the system of
: naming of hydrocarbons. According to IUPAC
system of nomenclature, hydrocarbons are named
1. Saturated hydrocarbons with the formula, prefix + word root + suffix.

2. Unsaturated hydrocarbons

1. Saturated hydrocarbons

Hydrocarbons like ethane, propane, butane, etc. have a single covalent bond between
carbon atoms. Such type of hydrocarbons are called saturated hydrocarbons. The
hydrocarbons containing a single covalent bond between two carbon atoms are called
saturated hydrocarbons. These hydrocarbons are stable in nature and nothing can be
added in these compounds and hence are called saturated hydrocarbons.

Saturated hydrocarbons are less reactive. So, they are also called paraffins. Saturated
hydrocarbons are commonly known as alkanes. Their general formula is CnH2n+2 where
'n' represents the number of carbon atoms in the given hydrocarbon which may be 1, 2,
3, 4, 5, ………

The first ten members of alkane series (saturated hydrocarbons) with their IUPAC name,
molecular formula, condensed formula and structural formula are given below:

1. Methane : CH4 Do You Know
Molecular formula
H Methane is the smallest known
hydrocarbon. It consists of one carbon
Structural formula : H C H atom and four hydrogen atoms.

H
220 GREEN Science (Chemistry) Book-10

Condensed formula : CH4 H
2. Ethane

Molecular formula : C2H6

H

Structural formula : H C C H

HH H

Condensed formula : CH3 – CH3
3. Propane

Molecular formula : C3H8

HH

Structural formula : H C C C H

H HH H

Condensed formula : CH3 – CH2 – CH3
4. Butane

Molecular formula : C4H10

H HH

Structural formula : H C C C C H

H HH H H H
C
Condensed formula : CH3 – CH2 – CH2 – CH3
5. Pentane
Molecular formula : C5H12

H HH H

Structural formula : H C C C C

H HH H H H

Condensed formula : CH3 – CH2 – CH2 – CH2 – CH3
6. Hexane

Molecular formula : H6H14

H HH HH

Structural formula : H C C C C C C H

H HH HHH

Condensed formula : CH3 – CH2 – CH2 – CH2 – CH2 – CH3

GREEN Science (Chemistry) Book-10 221

7. Heptane
Molecular formula : C7H16

H HH H H H H

Structural formula : H C C C C C C C H

H HH H H H H H

Condensed formula : CH3 – CH2 – CH2 – CH2 – CH2 – CH2 –CH3
8. Octane
Molecular formula : C8 H18

H HH H H H H H

Structural formula : H C C C C C C C C

H HH H H H H H H

Condensed formula : CH3 – CH2 – CH2 – CH2 – CH2 – CH2 – CH2 – CH3
9. Nonane
Molecular formula : C9H20

H HH H H H H H H

Structural formula : H C C C C C C C C C

H HH H H H H H H

Condensed formula : CH3 – CH2 – CH2 – CH2 – CH2 – CH2 – CH2 – CH2 – CH3
10. Decane

Molecular formula : C10H20

H HH H H H H H H H

Structural formula : H C C C C C C C C C C H

H HH H H H H H H H

Condensed formula : CH3 – CH2 – CH2 – CH2 – CH2 – CH2 – CH2 – CH2 – CH2 – CH3

2. Unsaturated Hydrocarbons
Hydrocarbons like ethene, propene,, butene, etc. have a double covalent bond between
any two carbon atoms. Similarly, hydrocarbons like ethyne, propyne, butyne, etc. have a
triple covalent bond between any two carbon atoms. Such type of hydrocarbons are called
unsaturated hydrocarbons. The hydrocarbons having a double covalent bond or a triple
covalent bond between any two carbon atoms are called unsaturated hydrocarbons. Some
atoms or molecules can be added in these hydrocarbons. So they are called unsaturated
hydrocarbons. The general formula of unsaturated hydrocarbons may be CnH2n or CnH2n – 2.
Unsaturated hydrocarbons are unstable in nature.

222 GREEN Science (Chemistry) Book-10

On the basis of type of bond between any two carbon atoms, unsaturated hydrocarbons
are of two types. They are as follows:

i. Alkenes ii. Alkynes

i. Alkenes

Hydrocarbons like ethene (H2C = CH2), propene (H2C = CH – CH3), etc. have a double
covalent bond between any two carbon atoms. Such types of hydrocarbons are called
alkenes. The hydrocarbons having a double covalent bond between any two carbon atoms
are called alkenes. Their general formula is CnH2n. Ethene, propene, butene, pentene, etc.
are some examples of alkenes. In alkenes, the first member consists of two carbon atoms
having a double covalent bond between them.

The first nine members of alkene series with their IUPAC name, molecular formula,
structural formula and condensed formula are given below:

1. Ethene H Do You Know
Molecular formula : C2H4
H Alkenes are also called olefins
HH C because they produce oil-like
substances.
Structural formula :
Alkenes are more reactive than
HC C alkanes.

Condensed formula : H2C = CH2 When alkenes react with sufficient
2. Propene hydrogen, they form alkanes.
Molecular formula : C3H6
H The general formula of alkenes is
HH CnH2n.

Structural formula : H C C H

H

Condensed formula : H2C = CH – CH3
3. Butene
Molecular formula : C4H8

H HH

Structural formula : H C C C C H

HH H

Condensed formula : H2C = CH – CH2 – CH3

4. Pentene
Molecular formula : C5H10

H HH H

Structural formula : H C C C C C H

HHH

Condensed formula : H2C = CH – CH2 – CH2 – CH3

GREEN Science (Chemistry) Book-10 223

5. Hexene
Molecular formula : C6H12

H HH H H H

Structural formula : H C C C C C C H

HHHH

Condensed formula : H2C = CH – CH2 – CH2 – CH2 – CH3

6. Heptene
Molecular formula : C7H14

H HH H H H H

Structural formula : H C C C C C C C H

HHHHH

Condensed formula : H2C = CH – CH2 – CH2 – CH2 – CH2 – CH3

7. Octene
Molecular formula : C8H16

H HH H H H H H

Structural formula : H C C C C C C C C H

HHHHHH

Condensed formula : H2C = CH – CH2 – CH2 – CH2 – CH2 – CH2 – CH3

8. Nonene
Molecular formula : C9H18

H HH H H H H H H

Structural formula : H C C C C C C C C C H

HHHHHHH

Condensed formula : H2C = CH – CH2 – CH2 – CH2 – CH2 – CH2 – CH2 – CH3

9. Decene
Molecular formula : C10H20

H HH H H H H H H H

Structural formula : H C C C C C C C C C C H

HHHHHHHH

Condensed formula : H2C = CH – CH2 – CH2 – CH2 – CH2 – CH2 – CH2 – CH2 – CH3

224 GREEN Science (Chemistry) Book-10

ii. Alkynes

Hydrocarbons like ethyne (HC CH), propyne (HC C – CH3), etc. contain a triple
covalent between any two carbon atoms. Such type of hydrocarbons are called alkynes.
The unsaturated hydrocarbons having a triple covalent bond between any two carbon
atoms are called alkynes. Their general formula is CnH2n – 2. Ethyne, propyne, butyne,
pentyne, etc. are some examples of alkynes.

Alkynes are also called acetylenes because the first member of alkyne series is called
acetylene. Alkynes are the most unstable and most reactive hydrocarbons.

The first nine members of alkyne series with their IUPAC name, molecular formula,
structural formula and condensed formulas are given below:

1. Ethyne

Molecular formula : C2H2 Do You Know
Structural formula : H C C H
Ethyne or acetylene is the smallest
Condensed formula : HC CH and the first member of alkyne
2. Propyne series.
Molecular formula : C3H4
Alkynes are the most reactive and
H unstable hydrocarbons.

The general formula of alkynes is
CnH2n–2.

When alkynes react with sufficient
hydrogen they form alkanes.

Structural formula : H C C C H

Condensed formula : HC H
3. Butyne
C – CH3

Molecular formula : C4H6

H H

Structural formula : H C C C C H

Condensed formula : HC HH
4. Pentyne
C – CH2 – CH3

Molecular formula : C5H8

HH H

Structural formula : H C C C C C H

HHH

Condensed formula : HC C – CH2 – CH2 – CH3

GREEN Science (Chemistry) Book-10 225

5. Hexyne

Molecular formula : C6H10

HHHH

Structural formula : H C C C C C C H

Condensed formula : HC HHHH
6. Heptyne
C – CH2 – CH2 – CH2 – CH3

Molecular formula : C7H12

HHHH H
C
Structural formula : H C C C C C C H

Condensed formula : HC HHHHH
7. Octyne
C – CH2 – CH2 – CH2 – CH2 – CH3

Molecular formula : C8H14

HHHHHH

Structural formula : H C C C C C C C C H

Condensed formula : HC HHHHHH
8. Nonyne
C – CH2 – CH2 – CH2 – CH2 – CH2 – CH3

Molecular formula : C9H16

HHHHHHH

Structural formula : H C C C C C C C C C H

Condensed formula : HC HHHHHHH
9. Decyne
C – CH2 – CH2 – CH2 – CH2 – CH2 – CH2 – CH3

Molecular formula : C10H18

HHHHHHHH

Structural formula : H C C C C C C C C C C H

HHHHHHHH

Condensed formula : HC C – CH2 – CH2 – CH2 – CH2 – CH2 – CH2 – CH2 – CH3

226 GREEN Science (Chemistry) Book-10

Differences between saturated and unsaturated hydrocarbons

Saturated hydrocarbons Unsaturated hydrocarbons

1. They have a single covalent bond 1. They have a double or triple covalent

between carbon atoms. bond between any carbon atoms.

2. They are stable compounds . 2. They are unstable compounds.

3. They are less reactive. 3. They are more reactive.

4. Their general formula is CnH2n + 2. 4. Their general formula may be CnH2n
or CnH2n – 2.

Activity 1

Take a chart paper. Write molecular formula, structural formula and condensed formula
of the first ten numbers of alkane series and present it in the classroom.

Homologous series

Chemist studied the properties of hydrocarbons like methane, ethane, propane, butane,
pentane, etc. and found that these compounds have similar structure and chemical
properties. But the successive compounds differ by – CH2 group. Such a series of organic
compounds is called homologous series. The group of organic compounds having similar
structures and chemical properties in which the successive compounds differ by – CH2
group is called homologous series. The same general formula is used to denote all the
members of a homologous series. Methane, ethane, propane, butane, pentane, hexane,
heptane, octane, nonane and decane are the first ten members of alkane series. They are
represented by the same general formula. The first five members of homologous series of
alcohol are given below:

1. CH3OH (Methanol) 2. CH3CH2OH (Ethanol)
3. CH3CH2CH2OH (Propanol) 4. CH3CH2CH2CH2OH (Butanol)
5. CH3CH2CH2CH2CH2OH (Pentanol)

Alkyl radical

The group of organic compounds which is formed by removing one hydrogen atom from
alkane is called alkyl radical.

Examples : methyl radical (CH3+), ethyl radical (C2H5+), propyl radical (C3H7+), etc.
Alkyl radical is represented by CnH2n+1. It is denoted by 'R'.
CH4 – 1H CH3+ (methyl radical)
C2H6 – 1H C2H5+ (ethyl radical)
C3H8 – 1H C3H7+ (propyl radical)

GREEN Science (Chemistry) Book-10 227

Functional Group

Atoms or group of atoms like hydroxyl (– OH), ether (– O –), carboxylic acid (– COOH),
etc. determine the chemical properties of hydrocarbons, which are commonly known as
functional groups. An atom or group of atoms that determine the chemical properties of a
hydrocarbon is called a functional group. Alkyl radicals combine with functional groups
and from different types of organic compounds.

Some common functional groups and compounds formed by them are given below:

Functional group Structure Compounds formed
1. Hydroxyl (– OH) Alcohol
2. Ether (– O –) – OH Ether
–O–
3. Carboxylic acid ( – COOH) Acid
O

C OH

IUPAC system

The full from of IUPAC system is International Union of Pure and Applied Chemistry.
This system was introduced to maintain uniformity in the nomenclature of inorganic and
organic compounds throughout the world. On the basis of this system, a compound gets
only one name. It helps in understanding of a certain compound by its unique name
throughout the world.

Nomenclature of Hydrocarbons

1. First of all, the word root of the given hydrocarbon is found by counting the number
of carbon atoms in the given hydrocarbon as follows:

No. of carbon atoms Word root Notation

C=1 Meth – C1
C=2 Eth – C2
C=3 Prop – C3
C=4 But – C4
C=5 Pent – C5
C=6 Hex – C6
C=7 Hept – C7
C=8 Oct – C8
C=9 Non – C9
C = 10 Dec – C10

2. After finding the word root, – ane, – ene or – yne is added after the word root on the
basis of type of bond between carbon atoms. It is done as follows:

228 GREEN Science (Chemistry) Book-10

i. If a hydrocarbon has a single covalent bond among all the carbon atoms, – ane is
added after the word root.

HH

HC C H

HH

\ No. of carbon atoms = 2

Word root = Eth –
Type of bond = single covalent = + ane

\ Name of hydrocarbon = Eth + ane

= Ethane

ii. If a hydrocarbon has a double covalent bond between any two carbon atoms,
– ene is added after the word root.

H HH

Example: H C C C H

H

No. of carbon atoms = 3

\ Word root = Prop –

Type of bond between any two carbon atoms = double covalent = + ene

\ Name of hydrocarbon = Prop + ene

= Propene

iii. If a hydrocarbon contains a triple covalent bond between any two carbon atoms,
– yne is added after the word root.

Example :

HHH

HC C C C C H

HHH

No. of carbon atoms = 5

\ Word root = Pent

Type of bond between any two carbon atoms = triple covalent = + yne

\ Name of the hydrocarbon = Pent + yne

= Pentyne

GREEN Science (Chemistry) Book-10 229

Some Common Hydrocarbons

1. Methane

Methane is the simplest aliphatic hydrocarbon. Its molecular formula is CH4. It is the
smallest and first member of alkane series.

Molecular formula : CH4 Structural formula
Condensed formula: CH4
H

HC H

H

Methane gas is found is marshy places. So, it is also called a marsh gas. It is formed due
to decomposition of organic matter. Mathane gas is commonly found above the mineral
oil. This gas is found in gobar gas, biogas and sewage gas.

Methane gas is colourless, odourless and tasteless. It does not dissolve in water but
dissolves in organic solvents like ether, alcohol, etc.

Uses of methane
1. Methane gas is used as a source of heat (fuel) for cooking purpose in rural areas.

2. It is used to produce carbon black. Carbon black is used for making colour, paint,
shoe polish, ink, etc.

3. It is used in the manufacture of hydrogen gas.

4. It is used for making chloroform and carbon tetrachloride.

5. It is used for making methyl alcohol, formaldehyde, etc.

2. Ethane

Ethane is a saturated hydrocarbon having two carbon atoms. It is the second member of
alkane series. Its molecular formula is C2H6. Ethane gas is found along with methane in
natural gas, coal gas and petroleum mines.

Molecular formula : C2H6 Structural formula
Condensed formula: CH3 CH3
HH

HC C H

HH

Ethane gas is colourless, odourless and tasteless. It does not dissolve in water but dissolves
in organic solvents like ether, alcohol, etc.

Uses of ethane gas
1. Ethane gas is used for welding as it produces more heat while burning.

2. It is used as a source of heat for cooking purpose in the form of bio gas.

230 GREEN Science (Chemistry) Book-10

3. It is used for making shoe polish and diethyl ether.
4. It is used for making ethyl alcohol (ethanol).

3. Propane

Propane is a saturated hydrocarbon having three carbon atoms. It is the third member of
alkane series. Its molecular formula is C3H8.

Propane gas is found in natural gas and petroleum mines. This gas is colourless and
odourless. It does not dissolve in water but dissolves in organic solvents like ether,
alcohol, etc.

Molecular formula : C3H8 Structural formula
Condensed formula: CH3 CH2 CH3
H HH

HC C C H

Uses of propane H HH

1. Propane gas is highly inflammable. So it is used as a fuel.

2. It is used for cooling purpose in petroleum industries.

3. It is used for making propyl alcohol and other organic compounds.

4. It is used in gas lighters.

4. Butane

Butane is a saturated hydrocarbon having four carbon atoms. It is the fourth member
of alkane series. Its molecular formula is C4H10. Butane gas is found in natural gas and
petroleum mines. This gas is colourless and odourless. Butane is insoluble in water but
soluble in organic solvents like alcohol, ether, etc.

Molecular formula : C4H10 Structural formula
Condensed formula: CH3 CH2 CH2 CH3
H HHH

HC C C C H

H HHH

Uses of butane
1. Butane gas is used in LPG (liquefied petroleum gas) along with methane because

butane gas easily becomes liquid on applying pressure.

2. It is used as a raw material for making synthetic rubber.

Isomers and Isomerism

Isomers are the organic compounds having similar molecular formula but different
structures and properties. Similarly, the existence of two or more organic compounds
having the same molecular formula but different structures nad properties is called
isomerism.

GREEN Science (Chemistry) Book-10 231

For example,

Butane (C4H10) shows isomerism. The two isomers of butane are m-butane and iso-butane.

H

H HHH H CH
HH

HC C C C H HC C C H

H HHH H HH

n-butane (C4H10) iso-butane (C4H10)
(Straight chain) (Branched chain)

Pentane also shows isomerism. The three isomers of Pentane are n-pentane, iso-pentane
and neo-pentane.

H

H HHHH H CH
H HH

HC C C C C H HC C C C H

H HHHH H HHH

n-pentane (C5H12) iso-pentane (C5H12)

H

H CH
HH

HC C C H

HH
H HH

H

neo-pentane (C5H12)

Alcohol

The organic compound containing hydroxyl group (– OH) is called alcohol. Alcohol is
prepared from alkane by replacing one or more hydrogen atom/s by hydroxyl radical/s.
The general formula of alcohol is CnH2n+1(OH). The functional group found in an alcohol
is hydroxyl (–OH) group.

Examples of alcohol

1. Methyl alcohol (CH3 – OH)

232 GREEN Science (Chemistry) Book-10

2. Ethyl aocohol (CH3 – CH2 – OH)
3. Propyl alcohol (CH3 – CH2 – CH2 – OH), etc.

On the basis of number of hydroxyl groups, alcohols are of three types.
a. Monohydric alcohol
b. Dihydric alcohol
c. Trihydric alcohol

i. Monohydric alcohol

It is the alcohol having only one hydroxyl group (–OH). It can be prepared by replacing
one hydrogen atom of an alkane by a hydroxyl radical (OH).

Examples:

Methyl alcohol (CH3OH)
Ethyl alcohol (C2H5OH)
Propyl alcohol (C3H7OH)
The method of formation of monohydric alcohols is given below:

HH

HC H –H H C OH
+ OH

H H

(Methane) (Methyl alcohol or Methanol)

HH HH

HC C H –H H C C OH
+ OH

HH HH

(Ethane) (Ethyl alcohol or ethanol)

HH H HH H

HC C C H –H H C C C OH
+ OH

HH H HH H

(Propane) (Propyl alcohol or propanol)

ii. Dihydric alcohol

It is the alcohol having two hydroxyl groups (– OH). It can be prepared by replacing two
hydrogen atoms of ethane by two hydroxyl (OH) radicals.

GREEN Science (Chemistry) Book-10 233

Example : Ethyl glycol HH

HH HCC H

HC C H –2H OH OH
+ 2(OH)
Ethyl glycol
HH

(Ethane)

iii. Trihydric alcohol

It is the hydrocarbon having three hydroxyl groups. It can be prepared by replacing three
hydrogen atoms of propane by three hydroxyl (OH) groups.

Example : Glycerol HH H

HH H

HC C C H –3H H C C C H
+ 3(OH)

HH H OH OH OH

(Propane) (Glycerol or Glycerine)

Some Common Alcohols and their Uses

1. Methyl alcohol

Methyl alcohol is a monohydric alcohol. Its IUPAC name is methanol and molecular
formula is CH3OH. The structural formula of methyl alcohol is given below:

H

H C OH

H

Methyl alcohol is the first member of monohydric alcohol series. It is prepared by replacing
one hydrogen atom of methane by one hydroxyl group.

HH

HC H –H H C OH
+ OH

H H

(Methane) (Methyl alcohol)

Uses
1. Methyl alcohol is used for making methylated spirit.
2. It is used for making perfume, dyes, colour, medicine, etc.
3. It is used as fuel in spirit lamp as it produces heat without smoke.
4. It is used in dry cleaning.

234 GREEN Science (Chemistry) Book-10

5. It is used to dissolve fat, oil, paint, varnish, etc.
5. It is used for making formaldehyde which is used to make bakelite in plastic industries.
7. It is used for making synthetic fibers.
8. It is used for making methyl chloride.

2. Ethyl alcohol

The molecular formula of ethyl alcohol is C2H5OH and condensed formula is CH3CH2OH.
It is the second member of monohydric alcohol series. It can be prepared by replacing one
hydrogen atom of ethane by one hydroxyl radical. The IUPAC name of ethyl alcohol is
ethanol. It is commonly known as drinking alcohol.

HH HH

HC C H –H H C C OH
+ OH

HH HH

(Ethane) (Ethyl alcohol or ethanol)

Uses
1. Ethyl alcohol is used as a thermometric liquid in alcohol thermometer.
2. It is used for making hard drinks like whisky, rum, vodka, wine, beer, etc.
3. It is used in biology lab to preserve specimen.
4. It is used in hospitals, clinics, health posts, etc. to clean cuts and wounds.
5. It is used for manufacturing polythene, terylene, soap, colour, paint, etc.
6. It is used as a solvent to dissolve resin, fat, oil, paint, etc.
7. It is used for making chloroform, ether, iodoform, etc.
8. It is used as a fuel.
9. It is used for making medicine.
10. It is used for making synthetic rubber.

3. Glycerol

Glycerol is a trihydric alcohol having sweet taste. The word glycerol has been derived from
the Geek word 'glyceros' which means sweet in taste. Glycerol is also called glycerine.
Glycerol is a thick and colourles liquid having sweet taste. It is soluble in water and
alcohol but insoluble in ether. The structural formula of glycerol its given below:

HH H

HCC C H

OH OH OH

The IUPAC name of glycerol is propane 1, 2, 3 triol. The molecular formula of glycerol is
C3H5 (OH)3.

GREEN Science (Chemistry) Book-10 235

Glycerol is prepared by replacing three hydrogen atoms (one from each carbon) by three
hydroxyl radicals.

HH H HH H

HC C C H –3H H C C C H
+ 3(OH)

HH H OH OH OH

(Propane) Glycerol

Uses
1. Glycerol is used in face creams, lip guards, etc. to prevent skin from cracking.
2. It is used for making printing ink and ink for stamp pads.
3. It is used as a sweetening agent in sweet house, confectioneries, beverages and

medicines.

4. It is used for making high quality soap, lotion, cosmetics and shaving creams.
5. It is used for moistening tobacco.
6. It is used for preserving foods and fruits.

7. It is used as a lubricant in watches.

4. Glucose

Glucose is a water-soluble white crystalline powder. Its molecular formula is C6H12O6. It
is also called dextrose. Glucose is one of the three monosachharides that are used directly
by our body to produce ATP (Adenosene triphosphate).

Glucose is formed during photosynthesis from water and carbon dioxide in the presence
of sunlight and chlorophyll. Similarly, glucose is broken down into water, carbon dioxide
and energy during respiration.

Glucose can be obtained by hydrolysis of carbohydrates like sugar, milk, cellulose, etc.
found in foods and fruits. Glucose is an important source of energy in most organisms,
i.e. bacteria to human beings.

The taste of glucose is sweet. Glucose is a carbohydrate and monosachharide sugar.
Glucose is found in fruits and honey. It helps in transportation of free sugar in the blood
of animals. It is used as the main source of energy essential for cells. It also helps to
maintain balance in metabolic activities. Glucose is both beneficial and harmful for
animals.

High sugar level in blood causes swelling of Do You Know
different parts of body. On the other hand, low
sugar level in blood is also harmful for the body. The word glucose has been derived from
Therefore, there should be adequate amount of Greek word 'glukus' which means sweet
glucose in our body to live a healthy life. in taste.

236 GREEN Science (Chemistry) Book-10

Activity 2

Take a chart paper and prepare a list of the hydrocarbons that are used in our daily
life. Also, mention their uses.

Present your work in your class.

Key Concepts

1. The compounds which are obtained from living beings and contain hydrocarbon
are called organic compounds.

2. The organic compounds made of carbon and hydrogen are called hydrocarbons,
e.g. Methane (CH4), ethane (C2H6), propane (C3H8), propane (C3H6).

3. The hydrocarbons containing a single covalent between carbon atoms are called
saturated hydrocarbons.

4. Saturated hydrocarbons are less reactive. So, they are also called paraffins.

5. The hydrocarbons having a double covalent bond or a triple covalent bond between
any two carbon atoms are called unsaturated hydrocarbons.

6. The group of organic compounds having similar structures and chemical properties
in which the successive compounds differ by – CH2 group is called homologous
series.

7. The group of organic compounds which is formed by removing one hydrogen atom
from alkane is called alkyl radical.

8. An atom or group of atoms that determine the chemical properties of a hydrocarbon
is called a functional group.

9. The full from of IUPAC system is International Union of Pure and Applied
Chemistry.

10. Ethane is a saturated hydrocarbon having two carbon atoms. Its molecular formula
is C2H6.

11. The organic compound containing hydroxyl group (– OH) is called alcohol. Alcohol
is prepared from alkane by replacing one or more hydrogen atom/s by hydroxyl
radical/s.

12. Ethyl alcohol is used as a thermometric liquid in alcohol thermometer. It is also
used for making hard drinks like whiskey, rum, vodka, wine, beer, etc.

13. Glycerol is a thick and colourless liquid having sweet taste. It is soluble in water
and alcohol but insoluble in ether.

14. Glucose is a water-soluble white crystalline powder. Its molecular formula is
C6H12O6. It is found in fruits and honey. It helps in transportation of free sugar in
the blood of animals.

GREEN Science (Chemistry) Book-10 237

Sequential General Exercise 1

1. Choose the best answer from the given alternatives.
a. Which of the given hydrocarbons is saturated?

Propene Propane Propyne Butene

b. Which of the following is the general formula of alkene?

CnH2n CnH2n + 1 CnH2n+2 CnHn
ethanol
c. Which of the following is the IUPAC name of drinking alcohol?

methanol ethylene ethanol

d. Which of the following is the molecular formula is glycerol?

C2H5OH C3H5(OH)3 C3H5(OH)2 C2H5(OH)2

e. Which of the given organic compounds is used in face creams and sweets?

glycerol alcohol glucose ethane

2. Answer the following questions.
a. What is a hydrocarbon? Give any three examples.
b. What are the sources of hydrocarbons?
c. Name two types of hydrocarbons.
d. What are saturated hydrocarbons? Give examples.
e. Define alkanes. Write their general formula and five examples.
f. What are unsaturated hydrocarbons? Give any five examples.
g. Define alkenes with any three examples.
h. What are alkynes? Write any four examples.
i. Write down the general formula of alkenes and alkynes.
j. What is meant by homologous series? Explain with examples.
k. Define functional group with any two examples.
l. Write down the full from of IUPAC.

3. Write down the molecular formula, structural formula and condensed formula of
the given organic compounds:

a. ethane b. butane

238 GREEN Science (Chemistry) Book-10

c. ethyne d. propene
e. pentane f. pentyne
g. octane h. octene
i. acetylene j. ethyl alcohol

4. Write down the molecular formula, source, two features and two uses of

a. methane b. ethane

c. propane d. butane

5. What is alcohol? Write down the general formula of alcohol.
6. How is alcohol prepared? Write with examples.
7. Name three types of alcohol with one example of each.
8. Write down the structural formula and three uses of methyl alcohol.
9. Write down the structural formula and three uses of ethyl alcohol.
10. What is glycerol? Write its structural formula and three uses.
11. What is glucose? Write down its molecular formula and use in the body.
12. Why is glucose necessary for our body?

13. Give reason:
a. Alkanes are called saturated hydrocarbons.
b. Alkenes and alkynes are called unsaturated hydrocarbons.
c. Alkenes are also called paraffins.
d. Alkynes are called acetylenes.
e. Methanol is called monohydric alcohol.
f. Glycerol is called trihydric alcohol.

14. Differentiable between:
a. Saturated hydrocarbons and Unsaturated hydrocarbons
b. Alkanes and Alkenes
c. Alkenes and Alkynes
d. Butane and Butyne
e. Ethane and Ethyne
f. Monohydric alcohol and Trihydric alcohol

15. Name the given hydrocarbons. H C CH
a. H b.

H C OH

H

GREEN Science (Chemistry) Book-10 239

c. H H H d. HH H

HC C C H HCC C H

H OH OH OH

e. HH

H C C OH

HH

16. Name any two organic compounds that are used at our homes. Also, write down
the main use of each.

Grid-based Exercise 2 (1 Mark Each)

Group ‘A’ (Knowledge Type Questions)

1. What is a hydrocarbon ?
2. How many types of hydrocarbon are there ? Write them.
3. What is the full form of IUPAC ?
4. Where is propane gas found ?
5. What are isomers ?
6. Write down the structural formula of butane.
7. What is glycerol ?
8. Write any two properties of glycerol.
9. What is glucose?
10. Write the molecular formula of glucose.
11. What type of hydrocarbons are called paraffins ?
12. Define unsaturated hydrocarbon.
13. Name the hydrocarbon which is used to make chloroform.
14. Draw structural formula of ethyl alcohol.
15. What is homologous series ?

Group ’B’ (Understanding Type Questions) (2 Marks Each)

16. Write any two differences between saturated hydrocarbon and unsaturated
hydrocarbon.

17. Butane is called a saturated hydrocarbon, why?

18. Propene is called an unsaturated hydrocarbon, why?

19. Glucose is both useful as well harmful for animals. Justify this statement.

240 GREEN Science (Chemistry) Book-10

20. Write any two differences between Propane and Propyne.

21. What type of hydrocarbon is called an unsaturated hydrocarbon? Write with one
example.

22. What is isomerism ? Write with an example.

23. Methane is called a hydrocarbon, why?

24. Acetylene is an unsaturated hydrocarbon. Write down its cause on the basis of its
structural formula.

25. What happens when the amount of glucose becomes more or less than the required
amount in human blood?

Group ‘C’ (Application Type Questions) (3 Marks Each)

26. Write any three uses of methane gas. HH

27. Write the name and three uses of the compound whose structural H C C OH
formula is given alongside: HH

28. Write down three uses of glycerine.

29. Write any three uses of ethyl alcohol. OH OH OH

30. Write down the name and two uses of given compound. HC C CH

H HH

Group ‘D’ (Higher Abilities Type Questions) (4 Marks Each)

31. What are the compounds having the following structural formula? Write the type of
hydrocarbon on the basis of bond. Write with reason.

i. H H ii. H H H

HC C C H C C C OH

HHH

32. Mention the method of naming hydrocarbons.

33. Is the given hydrocarbon saturated or unsaturated? H H

Name the compound formed by the reaction of above H C C C C H

compound with sufficient hydrogen. Also, give one use H HHH
of that compound.

34. What are the compounds of the following structural formula ? Write the type of
hydrocarbon on the basis of the bond. Write with reason.

i. H H H ii. H – C = C – H

HC C C H

H HH

35. Write the name of compound and its structural formula which is formed by
displacement of three hydrogen atom with three hydroxide radical from propane
through various chemical reactions. Write a short note on glucose.

GREEN Science (Chemistry) Book-10 241

UNIT Materials Used

13 in Daily Life

Weighting Distribution Theory : 10 Practical: 0

Before You Begin

Chemistry is the branch of science in which we study about
different types of chemical substances. Among many branches
of chemistry, industrial chemistry is one of them. In industrial
chemistry, we study about formation, characteristics and use
of chemicals that are used in our daily life. We use a variety of
materials like cement, glass, ceramics, plastics, soap, detergent,
insecticides, etc. in our daily life. In this unit, we will study
some common materials of daily use and chemical pollution in
brief. Similarly, we will study the ways to get rid of chemical
pollution and solid waste management.

Learning Objectives Syllabus

After completing the study of this unit, students will be able to: • Cement and uses of cement
i. introduce cement, glass, ceramics, plastics, soap and • Glass and its types
• Ceramics
detergent and to explain their utilities. • Plastics
• Soap and detergent
ii. explain the role of compost manure in agriculture. • Fertilizers (compost fertilizer

iii. describe chemical pollution caused by plastics, and chemical fertilizers)
chemical fertilizers, synthetic fibers, colours and • Chemical pollution
insecticides. • Ways to get rid of chemical

iv. analyze the chemical pollution caused due to over use pollution
of chemical fertilizers. • Solid waste management

v. identify, demonstrate and utilize biodegradable and
non-biodegradable wastes.

Glossary: A dictionary of scientific/technical terms

cement : a fine gray powder which sets hard when mixed with water and is dried

ceramics : the hydrated alumina silica used for making cups, plates, dishes, etc.

biodgradable : which decomposes due to action of microbes

non-biodegradable : which does not decompose due to action of microbes

insecticide : the chemical substances which are used to kill insects

fertilizers : the substances that are used to increase the fertility of soil

water proof : which does not allow water to enter through it

paste : a soft, wet mixture of usually a powder and a liquid

242 GREEN Science (Chemistry) Book-10

Materials used in daily life

Cement

Cement is a fine gray powder made by Fig. Fig.13.1
grinding limestone (CaCO3) and special
type of clay (Al2O3.SiO2). It is used in Cement
various construction works. When
cement is mixed with sand and water
and allowed to set, it becomes as hard as
stone. In Nepal, production of cement was
started in 1976 AD by Hetauda cement
factory. The production of cement was
started in England in 1825 AD, Germany
in 1855 AD, Belgium in 1855 AD, USA in
1972 AD and India in 1904 AD.

The raw materials which are essential for production of cement are as follows:

i. Limestone (CaCO3)
ii. Special type of clay (Al2O3.SiO2)

Manufacture of cement

Crushing, grinding and finish
grinding are the three steps involved in
the manufacture of cement. First of all,
limestone pieces are grinded in a grinder
to get the pieces of about 2cm. Then the
crushed limestone pieces are mixed with
clay in ratio 2:1. Then the mixture is again
ground to obtain fine powder which is
mixed with water to form cement slurry.

The cement slurry is passed through a
tall rotary kiln. Inside the kiln, cement 13.2

slurry is heated at 1400°C to 1600°C. Rotary kiln for making cement

At this high temperature, chemical reaction takes place. As a result, cement clinker is

obtained in the form of marble-sized balls. The cement clinker is allowed to cool and

is mixed with 2 to 5% of gypsum. Then the mixture is ground to obtain fine powder of

cement. Then the cement is packed in air-proof sacks and transported for storage.

The chemical reaction involved in manufacture of cement is given below:

Limestone + Aluminium oxide + Silicon dioxide Calcium silicate + Calcium aluminate

CaCO3 + Al2O3 + SiO2 CaSiO3 + CaAl2O3
Cement

GREEN Science (Chemistry) Book-10 243

Uses of cement

1. Cement is used for making mortar which Do You Know
is used for joining bricks, plastering
walls, roofs, etc. Mortar is the mixture of cement, sand
and water.
2. Cement is used for making concrete by
mixing cement, sand, water and gravel Gypsum is added to the cement to
(pebbles). Concrete is used for flooring increase the setting time of cement
and roofing. It is also used for making when mixed with water.
walls and pillars.

3. Cement is used for making RCC (Reinforced Cement Concrete). It is a mixture of
cement, gravel, sand and water in an iron framework. It is used for making framework
of houses and buildings, gutters, tunnel, bridges, etc.

Fig.13.3Concrete RCC
Fig. Mortar

Glass

Glass is a solid and transparent
industrial material. It is a super-cooled
liquid because it flows downwards very
slowly. Glass is a homogeneous mixture
of alkali metals and alkaline earthmetals.
The main raw material of glass is silica
which is found in sand. Different types
of glasses are used in our daily life.

We prepare glass by heating the
mixture of silica, sodium carbonate 13.4

and potassium carbonate. As a result, Silica glass

silicates are formed. Actually, glasses are silicates of metals. Glass neither exists in solid

state nor in liquid state. So, it is considered as the fourth state of matter.

Silica glass or Quartz glass

When silica is heated at about 1600°C, it melts. When it is cooled it forms a crystalline
substance which is known as crystalline glass or silica glass.
Pure silica (SiO2) 1600°C Quartz glass

244 GREEN Science (Chemistry) Book-10

Silica glass does not react with acid, water and other chemical substances. This glass has
flexibility. So there is no effect of change in temperature in this glass.

Silica glass is used to prepare glass glue, laboratory equipment and electrical equipment.

Water glass

Water glass is prepared by heating silica with sodium carbonate or potassium carbonate
at about 800°C. Actually, water glass is a sodium silicate or potassium silicate.

The chemical reaction involved in preparation of water glass is given below:
SiO2 + Na2CO3 800°C Na2SiO3 + CO2
SiO2 + K2CO3 800°C K2SiO3 + CO2
Water glass dissolves in water. So it is called water glass. This glass is used for making
silica garden, fire proof materials, glass paste and gum.

Ordinary glass or Soda lime glass

Ordinary glass is the glass which is prepared by heating silica with sodium carbonate and
calcium carbonate. When the mixture of silica (50%), sodium carbonate (15%), calcium
carbonate (10%) and glass pieces (25%) is heated at about 850°C in a tank furnace, ordinary
glass is obtained.
2SiO2 + Na2CO3 + CaCO3 850°C Na2SiO3.CaSiO3 + 2CO2
(Sodium Silicate and Calcium Silicate)

The liquid state of ordinary glass is poured into containers of various shapes through iron
pipe to make various materials. Then these materials are allowed to cool. This process is
called annealing. The glass materials become fragile without annealing. Ordinary glass
does not dissolve in water. This glass melts at low temperature. So it is called soft glass. It
is also called soda lime glass due to its composition.

Ordinary glass or soda lime glass is used for making:

i. window panes, bottles, light pipes and light bulbs.

ii. lens and prism.

iii. glass sheets and laboratory apparatus.

Hard glass

The glass which is prepared by heating silica with potassium carbonate and calcium
carbonate is called hard glass. It is also called potash-lime glass because it is made by
using potassium carbonate.
2SiO2 + K2CO3 + CaCO3 D K2SiO3.CaSiO3 + 2CO2
(Potassium silicate and Calcium silicate)

GREEN Science (Chemistry) Book-10 245

The melting point of hard glass is very high and hence can withstand very high temperature.
Therefore, hard glass is used to prepare electric bulb, tube light and laboratory equipment
like hard glass test tube, beaker, round bottom flask, etc. which are used at high temperature.

Borosilicate glass

The glass which is prepared by heating silica with sodium carbonate, calcium carbonate
and boric oxide is called borosilicate glass. It is very hard. So, it does not break easily. This
glass is also called pyrex glass.
5SiO2 + Na2CO3 + CaCO3 + B2O3 D Na2SiO3.CaSiO3.B2(SiO)3 + 2CO2

(Sodium cilicate.Calcium silicate.Boron silicate)

The effect of increase or decrease in temperature is very less in this glass due to presence
of boric oxide. This glass does not react with water and acids. Borosilicate glass is used for
making test tube, condenser, beaker, flasks, ovenware, ampoules, etc. due to its resistance
to heat and chemicals.

Lead crystal glass

The glass which is prepared by heating silica with potassium carbonate and lead monoxide is
called lead crystal glass. It is the homogeneous mixture of potassium silicate and lead silicate.
2SiO2 + K2CO3 + PbO D K2SiO3.PbSiO3 + CO2

(Potassium silicate and lead silicate)

It is also called flute glass. The refractive index of this glass is very high due to presence
of lead. Therefore, this glass is used for making lens, prism, radar tube, electric bulbs, TV
screens, spectacles, expensive drinking glass, etc. It is also used to cut UV-radiation.

Coloured glasses

We can find the glasses of different colour in market. Coloured glasses are prepared by
adding certain metal oxides in the mixture during the preparation of glasses. Some metal
oxides and the colour obtained in glass are mentioned below:

Colour obtained in glass Metal oxide to be added
Blue Cobalt oxide
White Tin oxide
Red Copper oxide
Black Nickel oxide
Violet
Manganese oxide
Yellow/brown Iron oxide
Green
Chromium oxide

Coloured glasses are used for making window panes, spectacles, glasses of car, train,
aeroplane, etc. They are also used for making decorative items.

246 GREEN Science (Chemistry) Book-10

A brief account of different types of glasses and compounds found in them is given below:

Types of glass Compounds found
1. Silica glass
2. Water glass Silica

3. Ordinary glass Silica and sodium carbonate or silica and
potassium carbonate
4. Borosilicate glass
Silica (50%), sodium carbonate (15%),
5. Hard glass calcium carbonate and glass pieces (25%)

6. Lead crystal glass Silica, sodium carbonate, calcium
carbonate and boric oxide

Silica, potassium carbonate and calcium
carbonate

Silica, potassium carbonate and lead
monoxide

Ceramics

The special type of clay which consists of
compounds of carbon, nitrogen, oxygen
and silica is called ceramics. It consists
of hydrated aluminium silicate. It may
contain carbonates of calcium and
magnesium and iron oxide.

The word ceramics has been derived Fig.
from the Greek word 'keramos' which
means potter's clay. Ceramics is used for 13.5
making cups, plates, crucibles, mortars,
tiles, bricks, etc. The clay which is used Ceramic cups
to make white ceramics is called kaolin.

To make ceramic utensils, special type of clay is collected, crushed and ground. Then it
is sieved to obtain fine powder. Then it is mixed with water to make paste. The paste is
cast into different materials (cup, plate, mortar, etc.) and these materials are dried in the
sunlight. Then these materials are heated in a kiln at high temperature. As a result, the clay
becomes hard and porous. Salt is added to make ceramic materials shiny and attractive.
These materials are again heated by applying tin oxide or lead oxide. This process is
called glazing. Glazing makes ceramic materials shiny, smooth, attractive and non-porous
(water-proof). We can polish the ceramic materials to make them more attractive.

Ceramic materials do not react with acid, base and water. They are not affected by increase
on decrease in temperature. They are bad conductors of heat and electricity. They do not
absorb water.

Ceramics is used for making cups, bowls, plates, etc. It is used for making false teeth and
bones. It is used for making bricks and tiles. It is used for making mortar and porcelain
basin.

GREEN Science (Chemistry) Book-10 247

Plastics

The man-made polymers which can be changed into various shapes are called plastics.
They are made by heating monomers like ethene, vinyl chloride, etc. The word plastic has
been derived from a Greek word 'plastico' which means 'capacity to change shape'.

All plastics contain numerous monomers connected together due to chemical process.
When monomers are heated, they combine and form a long chain called polymer. The
process of formation of polymer is called polymerization.

H HH H H HH H

...... + C = C + C = C + ...... Polymerization – C – C – C – C –

H HH H H HH H

Monomers Polymer

Types of plastics

There are two types of plastics. They are as follows:

1. Thermoplastic 2. Thermosetting plastic

1. Thermoplastic

The plastic which becomes soft and

flexible on heating and hard on cooling

is called thermoplastic. The molecules

of this plastic are connected in the form

of linear polymer. Therefore, it can be Fig.
Fig.
changed into various shapes. Examples:

Polythene, polysterine, polyvinyl 13.6
chloride (PVC), etc.
PVC, Polythene

2. Thermosetting plastic

The plastic which becomes hard on heating and cannot be changed into different shapes is
called thermosetting plastic. In this plastic, the molecules are combined to each other due
to cross-linking in the form of cross-linkage polymer. Therefore, thermoplastic cannot be
changed into various shapes after giving specific shapes. Examples: Bakelite, melamine,
urea, formaldehyde, etc.

Handle of pressure cooker Melamine

13.7
Bakelite

248 GREEN Science (Chemistry) Book-10

Bakelite is a thermosetting Fig.
plastic. It is made by
polymerization of carbolic 13.8
acid (C6H5OH) and
formaldelyde (HCHO). It
is very hard. It is used for
making switches, plugs,
sockets, handle of pressure
cooker, lid of bottles,
astrays, etc.

Different types of plastics and their uses

Plastics Uses
1. Polythene
2. PVC To make polybags, seat, polythene, etc.
3. Bakelite
To make raincoat, pipe, hand bag, bottles, sole of shoe, etc.
4. Polyster
To make switch, plug, socket, lid of bottle, handle of pressure
5. Polysterene cooker, astray, etc.

To make thermocol, materials for packaging, and insulating
materials

To make container, toys and cases of refrigerator and television

Characteristics of plastics

1. Plastics are bad conductors of heat and electricity.
2. They do not react with chemical substances.
3. Plastics can be recycled.
4. They are light. So, they can be transported easily.
5. They can be coloured easily.
6. They are transparent and unbreakable.
7. They do not rot.
8. They are cheap and durable.
9. They do not corrode.
10. They do not react with acids and bases.

Uses of plastics

1. Plastics are used for insulating because they are bad conductor of heat and electricity.
2. They are used for making bags, pipes, bottles, etc.
3. They are used for making furniture, tunnels and parts of vehicles and aeroplanes.
4. They are used for storing various chemicals.
5. They are used for making toys, statue, windows, etc.
6. They are used for making clothes.
7. They are used for making shoes, socks, nets, etc.

GREEN Science (Chemistry) Book-10 249

8. They are used for making water-proof materials.
9. They are used for making packing materials.
10. They are used for making kitchenwares.

Soap

Soap is a very important cleansing material. A Do You Know
soap is a sodium or potassium salt of higher fatty

acid. Sodium palmitate, sodium stearate and When soap is used for cleaning in hard
sodium oleate are the common examples of soap. water, it reacts with salts of calcium and

magnesium present in hard water and

Soap was discovered before 5000 years by the forms a brown layer on the clothes called

people of Babylone. They discovered the fact that scum, So soap is not suitable for cleaning
when animal fat is mixed with ash and water, the purpose in hard water.

mixture can be used as a cleansing agent. The

first soap was used in textile factory and to treat skin diseases.

The raw materials required for preparation of soap are given below:

i. Animal fat or vegetable oil ii. Sodium hydroxide

Simple soap is prepared by heating animal fat or vegetable oil (olive oil, coconut oil,
cotton oil, etc.) with sodium hydroxide and sodium chloride. The process of making soap
by heating animal fat or vegetable oil with sodium hydroxide and sodium chloride is
called saponification.

The chemical reaction involved in saponification is given below:

Fat/Oil + Sodium hydroxide Soap + Glycerol

C3H5 (OOCR)3 + 3NaOH 3NaOOCR + C5H5 (OH)3

Where, R represents hydrocarbon series

i. R = C17 H35 (Stearate)

ii. R = C16H33 (Oleate)

iii. C15H31 (Palmitate)

Soap is not suitable to wash clothes with hard water as it forms a curdy precipitate (scum)
which is insoluble in water. Soap is biodegradable. So, it does not cause environmental
pollution.

Activity 1

Take a beaker and add 40 ml of vegetable oil into it.
Take another beaker and make a solution of 15 gram sodium hydroxide in 50ml

water.
Mix both solutions and heat the mixture by stirring it.
Add some salt and soda.
Pour the mixture in a container of desired shape to make soap.
This process is called saponification.

250 GREEN Science (Chemistry) Book-10