Lab work instructions for Fundamentals of Chemistry

FUNDAMENTALS OF CHEMISTRY

Laboratory Work Instructions

Lecturer : Eliyawati, M.Pd

INTERNATIONAL PROGRAM ON SCIENCE EDUCATION
FACULTY OF MATHEMATICS AND SCIENCE EDUCATION

UNIVERSITAS PENDIDIKAN INDONESIA

TABLE OF CONTENT

1.State of Matter
2.Changes of State
3.Physical and Chemical Changes
4.Determining the Formula of MgO
5.Chemical Reactios
6.Stoichiometry of Reaction
7.Electrical Conductivity of Aqueous

Solutions
8.Redox Reaction
9.Electrochemical Cells
10.Build a Molecule Phet Lab
11.Geometry of Molecular Species (VSPER)
12.Natural Acid Base
13.pH of Acid Base Equilibrium
14.Natural-Artificial Food Coloring

INTERNATIONAL PROGRAM ON SCIENCE EDUCATION
FACULTY OF MATHEMATICS AND SCIENCE EDUCATION

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MEETING 1. FUNDAMENTALS OF CHEMISTRY

Name class

WORKSHEET: STATES OF MATTER

Objective

You would be able to differentiate the characteristic of solid,
liquid, and gas.

Material and Apparatuses

water 2 different cups pencil

ballon 2 transparent plastic bags

Procedures

A. solid state

Please prepare two different cups and pencil.
Put the pencil into the first cup and sequentially put the
pencil into the second cup.
Please observe what happen to the pencil.

Questions
1.Does the shape of pencil change when is placed in
different container?
2.Based in the first observation, what your conclusion about
solid material?

B. Liquid state
Please prepare a cup, transparent plastic bag and water.
Pour the water into a cup and plastic bag .
Please observe what happen to the water.

Questions
1.Does the shape of water is different between in cup and
plastic?
2.Based in the second observation, what your conclusion
about liquid material?

C. Gas state
Please prepare a balloon and plastic bag
Blow the balloon and plastic bag and tie for each

Questions

1.Does the shape of gas is different between in balloon and
plastic?

2.Based in the second observation, what your conclusion
about gas material?

Summary Table

State of matter Characteristic based on shape

Solid


Liquid


gas


Please open FunChem android Application !!
and and complate the table in the next page

State symbol Arrangement Particles arrangement
of of particles pictures

matter

Solid






Liquid





gas











































Practical activity

Substances Solid/liquid/ Reason
gas


Sauce




Hair gel



sponge


Wet clay

Maka terangkanlah kepadaku tentang air yang kamu minum.
Kamukah yang menurunkannya atau Kamikah yang

menurunkannya? Kalau Kami kehendaki, niscaya Kami jadikan
dia asin, Maka Mengapakah kamu tidak bersyukur?”
(QS: Al-Waqi’ah ayat 68-70)

MEETING 2. FUNDAMENTALS OF CHEMISTRY

WORKSHEET: CHANGES OF STATE

name : class:

Objective

Student will be able to describe the differences of changes of state

materials and apparatuses

Wax Watch glass
Butter Wire gauze
Matches Cold water
Spoon Tripod
Naphthalene balls / 2 beaker glass
camphor balls Test tube
Bunsen burner Water
ethanol

Procedure

1st Activity

1.Burn the candle/ wax, please observe the changes of state when the
wax is heated and when it cool down again.

2.Put a little butter in spoon and heated on the candle, after that blow
out the candle and please wait until the butter cool down. please
observe the changes of state of butter.

3.Don’t forget to take a picture!
4.Please complete the table!

2nd Activity

1.Please arrange the materials and apparatuses of second observation
like a picture below:
Watch glass, and cold water
Beaker glass
Naphthalene balls / camphor balls
Wire gauze
Tripod
Bunsen burner

2. Burn the Bunsen burner, and please observe the changes of state of
the naphthalene balls
3. Don forget to take a picture!
4. Please complete the table!

3rd Activity

1.Please arrange the material and apparatuses of third observation like a
picture below

Beaker glass

Water

Wire gauze

Tripod

Bunsen Burner

2. Pour a little of ethanol in test tube, put it into the hot water, and
please observe the changes of state of the ethanol
3. Don’t forget to take a picture!
4. Please complete the table!

Result

Figure Description

Figure Description







































Please open FunChem android Application !!
and complate the table in the next page

please determnine the arrangement of the
particles!!

Melting

Before After





symbol : symbol :
Freezing
After
Before





symbol : symbol :
sublimation
After
Before





symbol : symbol :

please determnine the arrangement of the
particles!!

Boiling

Before After





symbol : symbol :
Desposition
After
Before





symbol : symbol :

Good Job
Ananda !!!!

"Dan Kami turunkan air dari langit dengan
suatu ukuran; lalu Kami jadikan air itu
menetap di bumi, dan pasti Kami berkuasa
melenyapkannya"
Qs Al Mu'minun ayat 18

W O R K S H E E TMEETING 3. FUNDAMENTALS OF CHEMISTRY

physical and chemical
changes

Name: Class:

Objective

Students will be able to differentiate physical changes and
chemical changes

Material and
Apparatuses

A paper
scissors
Matches
Baking soda
Empty bottle
Vinegar
Balloon
Spoon

1st Activity

Procedure

1.Cut the paper into two pieces
2.Cut the first paper into several small pieces
3.Please burn the second paper with maches
4.please observe the different changes of those two

papers
5.Don’t forget to take a picture of each!
6.Please complete the table!

Result

Observations Figure Observations Result









Question

1. Does a paper that was cut into the small one change its
material properties?

2.Then what about the burned paper, does the material
change?

3.Can the ash from burned paper turn into paper again?

2nd Activity

Procedures

1.Please prepare a balloon, vinegar, baking soda and empty
bottle

2.Pour the vinegar into a bottle
3.Add three tablespoons of baking soda into the balloon
4.Without dropping the baking soda into the bottle, attach

the balloon into the hole of bottle as presented in the figure
below:

5. Pour the baking soda inside the balloon into the bottle and
please observe what happen to the balloon.
6. Don’t forget to take a picture
7. Please complete the table!

Result

Observation Figure Observation result
description







Please open FunChem android
Application !!

and complate the table of
conclusion in the next page

Conclusion

Observations physical/chemical Reason
changes


Small pieces


of paper


Burned paper


Vinegar +

baking soda

"yaitu (Allah) yang menjadikan api untukmu dari kayu yang
hijau, maka seketika itu kamu nyalakan (api) dari kayu itu.”

QS Yasin ayat 80

MEETING 4. FUNDAMENTALS OF CHEMISTRY

4.1 Determination of

the formula of magnesium
oxide

Aim

To find, by experiment, the formula of the compound magnesium oxide by burning a known
mass of magnesium metal in air.

Theory

Magnesium metal is a reactive metal which will, when heated, react with oxygen gas in air to
form solid magnesium oxide. When the reaction occurs, an intense white light is observed.

magnesium + oxygen ---+ magnesium oxide

Even at room temperature, magnesium metal reacts slowly with oxygen to produce the
oxide, so before the experiment starts it is necessary to remove the oxide layer on the
surface of the magnesium metal using some emery paper.
The formula of magnesium oxide can be found from the moles of oxygen gas which will
react with one mole of magnesium metal, using an empirical formula calculation.

Apparatus and chemicals

D eye protection
D crucible and lid
D Bunsen burner
D heat-resistant mat
D tripod
D pipe-clay triangle
D emery paper
D accurate balance
D tongs which meet
48 D 10cm of magnesium ribbon

Procedure 0

Throughout the practical the student should wear eye protection. !:!l

1 Clean a 15cm piece of magnesium ribbon by pulling the ribbon through a folded m
up piece of emery paper a few times - it should become shinier as you remove the ::0
magnesium oxide and other impurities from its surface.
:zs::
2 Weigh the crucible and lid. Make sure that the lid you are using overlaps the edges of the
crucible. Record the mass in the results section. ~
0z
3 Coil up your magnesium ribbon so that is fits onto the bottom of the crucible.
4 Weigh the crucible, lid and magnesium, again recording the mass in the results section. .0.,,
5 Place the crucible containing the magnesium, and the lid onto a pipe-clay triangle on a
-::Ic
tripod above a Bunsen burner.
6 Using a colourless Bunsen flame, heat the crucible strongly for about 15 minutes. Every .m.,,

5 minutes lift off the crucible lid, with the tongs, for 2-3 seconds. During this time 0
the magnesium metal will have reacted with the oxygen in the air. If it does not, keep
heating for another five minutes. ::0

+--- - - - - crucible :s::

~==::::~+:~=~- - pipe clay .C...
t riangle
' - - - + - 1 - - - magnesium )>
f----- tripod
1------< >-- - Bunsen burner Q

:s::

)>
G)

z

m

cV>

:s::

~
0m

0 49

c::::J ~:::f; ~;~~§§§- heat-resistant

mat
Figure 1

7 After the reaction has occurred, allow the crucible, magnesium oxide and lid to cool.

8 Reweigh the crucible, magnesium oxide and lid on the balance and record its mass in the
results section.

V'I 9 Re-heat the crucible for another 5 minutes, raising the lid once for a few seconds. Allow

z
0
the crucible, magnesium oxide and lid to cool before re-weighing them. Record the mass
~
9...I in the results section.

<{ 10 If the mass recorded in step 8 is the same as that in step 9, then the experiment is

V

...I finished. If the mass has changed, repeat step 9 until it is constant. Record the final

<{

V constant mass in the results section.

~
:w:c:
V
Method
I

>-
0::
1w-
~ 1 Why is the magnesium ribbon coiled up at the start of the experiment? [1]
Q
::c:

V

~
V'I

~

2 Why is it important to use a colourless Bunsen flame to heat the crucible? [2]

3 Why is a pipe-clay triangle used and not a gauze? [1]

4 Why is it important to raise the lid during the experiment? [1]

5 Why is it important only to raise the lid for a few seconds? [1]

6 Why does the heating have to be repeated until there is no change in the final mass of

the apparatus and its contents? [2]

50

Results and calculations [1] 0

Mass of crucible and lid = ........................................... g !:!l
Mass of crucible, lid and magnesium ribbon = ..•........•........•........•........•.... g
Mass of crucible, magnesium oxide and lid after 15 minutes= ........................................... g m
Final mass of crucible, magnesium oxide and lid after a further heating = ::0
g•••* ......................................
1 From your results, find the mass of magnesium used in the experiment. :s::
z
2 From your results, find the mass of oxygen gas from the air which has reacted [1] ~
with the magnesium in your experiment.
0z
3 Use the masses from 1 and 2 to complete the following calculation to obtain
the formula of magnesium oxide from your experiment. .0.,,

:-:Ic

.m.,,

0

::0

:s::

.C...

)>

.0.,,

:s::

)>

"z

m

cV>

:s::

~
0m

[4]

Table 1 Mg 0
mass/g

moles -- --
simplest ratio of moles
24 16

Conclusions [1]

What is the empirical formula of magnesium oxide from your data?

Evaluation

1 There are other gases in air which magnesium can react with to produce other products.

How could the procedure be changed to remove this problem? [2]

51

V'I 2 How could the procedure be improved to increase the accuracy of the data obtained? [1]

z
0
~
...I

9
<{

V

...I
<{

IV
Extension
V
I

~ Try to find out the names of at least two other gases found naturally in air which

I-

~ the magnesium metal could have reacted with. For each, write a balanced chemical

~ equation for the reactions which occur. [4]

V

~

V'I
~

52

MEETING 5. FUNDAMENTALS OF CHEMISTRY F

CHEMICAL REACTION

LECTURER (S): ELIYAWATI, M.PD

Name :
ID :
Date :

PURPOSE

1. To identify the chemical reaction
2. To write the chemical equation
3. To analyze reactants and products
4. To determine the coefficient in the chemical equation
5. To identify chemical change characteristics
6. To explain the law of conservation mass

BASIC THEORY

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FACULTY OF MATHEMATICS AND SCIENCE EDUCATION

UNIVERSITAS PENDIDIKAN INDONESIA

CHEMICAL REACTION

LECTURER (S): ELIYAWATI, M.PD

MATERIALS EQUIPMEQENUITPMENT F

Scissors (1)
Sand Paper (1)
Crucible tongs (1)
Spiritus Burner (1)
Test tube holder (1)
Test tube (6)
Test Tube rack (1)
One hole rubber stopper (1)
Glass tube (1)
Large Test Tube (1)
Stand (1)
Clamps (1)
Bosshead (1)

OBSERVATION

PROCEDURE OBSERVATIONS

1. Scrub a piece of copper and

magnesium wire until they are
shiny.
Hold the copper wire using
crucible tongs, place in the
hottest part of a burner flame for
1-2 minutes. Note the change and
appearance caused by burning
(Do the same procedure to the
magnesium wire).

PROCEDURE OBSERVATIONS
2. Carefully pour 5 mL of HCl(aq)
F
6 M into a dry test tube. Add a
small piece of zinc metal into
the acid. Note the change and
appearance.
Do the same procedure using
Mg wire.

3.

4.

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DATA ANALYSIS AND DISCUSSION F

PROCEDURE 1

What is the purpose of scrubbing the copper and magnesium wire?

Why do we use the hottest part of the burner flame to burn
copper/magnesium wire?

Are there any changes when copper/magnesium wire is burned?
Mention some chemical changes.

Write the chemical equation to describe what happens when chemical
reactions occur.

For each chemical equation, determine the reactants and products.

Balance the chemical equation.

Count the number of atoms of each element on both sides of the
arrows to determine whether the chemical equation is balanced.

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PROCEDURE 2

Are there any changes when Zinc/Magnesium is immersed into HCl
solution? Mention some chemical changes.

F

Write the chemical equation to describe what happens when chemical
reactions occur.

For each chemical equation, determine the reactants and products.

Balance the chemical equation.

Count the number of atoms of each element on both sides of the
arrows to determine whether the chemical equation is balanced.

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PROCEDURE 3 F

Is there any change when potassium chromate reacts with lead
nitrate? Mention it.

Write the chemical equation to describe what happens when chemical
reactions occur.

For each chemical equation, determine the reactants and products.

Balance the chemical equation.

Count the number of atoms of each element on both sides of the
arrows to determine whether the chemical equation is balanced.

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PROCEDURE 4 F

Mention some chemical change that happens in procedure 4.

Write the chemical equation to describe what happens when chemical
reactions occur.

For each chemical equation, determine the reactants and products.

Balance the chemical equation.

Count the number of atoms of each element on both sides of the
arrows to determine whether the chemical equation is balanced.

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ADDITIONAL DATA ANALYSIS F

1.Does the chemical reaction always make the chemical changes?
2.Are the total number of atoms of each kind before and after reaction
always same?
3.Do all chemical reactions always obey the law of conservation mass?
4.What is the law of conservation mass?
5.What is the chemical reaction?

CONCLUSION

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MEETING 6. FUNDAMENTALS OF CHEMISTRY

STOICHIOMETRY OF REACTION

LECTURER (S): ELIYAWATI, M.PD

Name : F
ID Number :
Date :

A. OBJECTIVES

1. Determine coefficient reaction based on precipitation formed.
2 Determine stoichiometry of acid-base reaction.

B. BASIC THEORY

A chemical reaction is a process in which one set of substances called reactants is
converted to new set of substances called products. In many cases, though, nothing
happens when or substances are mixed together, they retain their original properties
and composition. Just as symbols are used for elements and formulas for compounds,
there is a symbolic or shorthand way of representing a chemical reaction called
chemical equation.

All atoms present in the reactants must be accounted for among the products. In
other words, there must be the same number of each type of atom on the product side
and on the reactant side of the narrow. Making sure that this rule is followed is called
balancing chemical equation. The coefficients in balanced equation tell the number of
substances involved in a reaction. These coefficients also tell the number of moles of
substances in a reaction. For example:

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In the laboratory, coefficient in chemical reaction can be determined through
experimental data series results. One of simple way to determine coefficient of
reaction is continuous variation method. The basic principle of this method is in a
series of experiments, the total molar amount of reactants is made permanent, while
the molar amount of each changed regularly. Changes that occur as a result of the
reaction between the mixture of reactants (mass, volume, and temperature) is plotted
to the molar of each reactant in a graph, in order to obtain an optimum point.
Optimum point shows coefficient ratio for each reactant.

C. EQUIPMENT AND MATERIALS

EQUIPMENT MATERIAEQLSUIPMENT

Beakers 100 mL (6)
Graduated cylinder 25 mL (1)
Graduated cylinder 10 mL (1)
Thermometer (2)
Tray (1)
Ruler (1)

D. PROCEDURES
1. STOICHIOMETRY OF PRECIPITATION REACTION

b. Mix two kinds of solution and shake it.
c. let the mixture until precipitation is formed.
d. Measure the height of precipitation using ruler (mm).

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F

2. STOICHIOMETRY OF ACID-BASE REACTION

E. OBSERVATION TABLE

1. STOICHIOMETRY OF PRECIPITATION REACTION

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2.STOICHIOMETRY OF ACID-BASE REACTION

F

F. CHEMICAL REACTION AND CALCULATION F

Write chemical reaction based on your experiment (complete with phase)
and calculate moles of reactants and products.
1. Stoichiometry of Precipitation Reaction

2. Stoichiometry of Acid-Base Reaction

1. G.DATA ANALYSIS

1. STOICHIOMETRY OF PRECIPITATION REACTION

2. STOICHIOMETRY OF ACID-BASE REACTION F

a. What is the relationship between moles of substances and the temperature
changes in chemical reaction.
b. Make graph and plotted the change of temperature [Y] VS volume
NaOH/HCl[X]. Which experiment that has optimum point? Describe with
any scientific explanation.
c. Compare between the coefficient of reaction that you get from experiment
and the coefficient of reaction based on theory (chemical reaction). Explain
in detailed.
d. Mention some kinds of difficulties in your experiment and how to solve it

H. CONCLUSION

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MEETING 7. FUNDAMENTALS OF CHEMISTRY F

ELECTRICAL CONDUCTIVITY OF AQUEOUS SOLUTIONS
LECTURER (S): ELIY
AWATI, M.PD

Name :
ID Number :
Date :

OBJECTIVES :

• To observe electrical conductivity of substances in various aqueous solutions
• To determine of the solution is a strong or weak electrolyte
• To interpret a chemical reaction by observing aqueous solution conductivity.

BASIC THEORY :

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MATERIAL AND EQUIPMENTS
SAFETY

Be cautious with hydrochloric acid, nitric acid, sulfuric acid and acetic acid.
Although low in concentration, some individuals may have extreme skin sensitivities.

If you experience any tingling sensations or skin discolorations,
rinse immediately with large amounts of water for 15 minutes.

Inform your instructor ASAP.
Personal Protective Equipment (PPE) required: lab coat, safety goggles, closed-toe shoes.

Electrolyte tester Wash bottle with distilled water Large breaker

Small beakers Graduated Cylinder Funnel

Stirring rod Erlenmeyer Volumetric Flask

Acetic acid solution Ammonium hydroxide solution Sodium hydroxide solution

Citric Acid Solution Ethanol Solution Hydrochloric Acid Solution

Lead Nitrate Solution Sucrose Solution Sodium Chloride

Nitric Acid Solution Sulfuric Acid Solution Lead (II) Nitrate

EQUIPMENT PROCEDURE

1. Set the electrolyte tester.
2. Pour each solution.
3. Rinse the electrodes by using distilled water.
4. Test the conductivity of certain solution.
5. Rinse the electrodes by using distilled water and test another solution.

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OBSERVATION TABLE

NO SOLUT
ION OBSERV
ATION CONDUC
TIVITY STRONG, WEAK AND IONIZED, PARTIALLY
NON ELEC
TROLYTE
IONIZE
D, OR

NON IONIZED

1






2






3






4






5






6





7






8






9






10






11





12






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DATA ANALYSIS

1.Why must the electrodes on the conductivity apparatus, as well as all
the beakers, be rinsed with distilled water after each conductivity test?

F

2. Classify each of the following as non-ionized, partially-ionized, or
ionized

3. Write the chemical reaction

CONCLUSION

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Name : MEETING 8. FUNDAMENTALS OF CHEMISTRY
ID Number :
Date : REDOX EXPERIMENT
LECTURER (S): E
LIYAWATI, M.PD

F

1. Reaction of hydrochloric acid and zinc.

a. Place a piece of zinc metal into a test tube with 3 mL of a 6 M HCl solution.
b. Place a piece of copper metal into a test tube with 3 mL of a 6 M HCl solution.
Write the balanced equations and do the redox analysis

2. Reaction of nitric acid and copper.

UNDER THE FUME HOOD put a piece of copper metal into a 100 mL beaker with 5 mL
of a 8 mL HNO3 solution. Observe and record the changes. When the reaction has stopped,
fill the beaker with distilled water and leave it under the fume hood.
Write balanced equation for this reaction and do the redox analysis.

3. Metal activity series: zinc and copper.

Put a piece of metallic zinc into a 100 mL beaker and add with 3 mL of a 1 M
copper(II)sulfate solution. Observe and record the changes. Write a balanced equation for
this reaction and do the redox analysis. Which metal is more active: zinc or copper?

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MEETING 9. FUNDAMENTALS OF CHEMISTRY

6.1 Electrochemical cells:
chemical energy to
electrical energy

Aim

To make simple electrochemical cells, and to use the results obtained to put metals in an
order of reactivity.

Theory

An electrochemical cell is one in which chemical energy is changed into electrical energy. To
produce an electrochemical cell, two different metals are needed, an electrolyte and, in this
experiment, a voltmeter to show the voltage produced. Alternatively a bulb could be used,
which would light if the voltage produced was large enough. The voltage produced is large
if the reactivity of the two metals is very different.

In an electrochemical cell, the more reactive metal loses electrons to form metal ions, while
the less reactive metal gains electrons to convert its ions, from the solution, to form the metal.
To construct an electrochemical cell two half-cells are set up. These are connected together
by a salt bridge through which ions can move.

Apparatus and chemicals

D eye protection
D voltmeter
D 2 x wire leads with plugs to connect to the voltmeter
D 2 x crocodile clips for the other end of the leads
D 2 x 150cm3 beakers
D filter paper
D saturated potassium chloride solution
D cleaned pieces (1 cm x 3 cm) of metals: copper, lead, magnesium, iron, zinc, tin
D 0.1 mol/dm3solutions of the nitrates (or other suitable solutions) of copper, lead, magnesium,

74 iron, zinc and tin

Procedure .m...

Throughout the practical the student should wear eye protection. ~

1 Take the beaker and fold the piece of copper metal over the top. Clip a crocodile clip to g-:,;I:,
the copper metal, holding it in place in the beaker. Connect the other end of the lead to
the positive terminal of the voltmeter. ::c

2 Fill the beaker with the 1mol/dm3 copper nitrate solution so that the copper metal dips sm:
into it. This is known as a copper half-cell.
ri
3 Take your piece of lead, fold it over the top of the second beaker. Fill the beaker with the
1mol/dm3 lead(II) nitrate solution so that the lead metal dips into it. Connect the lead .).>..
metal to the other terminal on the voltmeter. This is a lead half-cell.
(')
V
.mc.;.;.

(')

::c

sm:

ri

.).>..

mz

m
:,;:,

C-<l

0

.m...

~

-I
:,;:,

ri

.).>..

mz

m
:,;:,
Cl

-<

salt bridge

electrode -- - - - - electrode

salt salt

- solution -solution

Figure 1

4 Finally, connect the two beakers together with a salt bridge which is made from a folded
piece of filter paper soaked in potassium chloride solution.

5 You should now see a voltage being recorded on the voltmeter. You have just made an
electrochemical cell - a battery. Record the voltage in the results table.

6 Repeat steps 3-5 for the other four metals, each time replacing the beaker and metal
connected to the copper half-cell (the lead half-cell in the first case) with half-cells of the
other metals.

Method [1]

1 Which metal is being used as the standard in this experiment?

75

t} 2 From the apparatus list can you see a piece of information about the solutions which is

!;:; used to ensure a fair test? [1]
C, [1J
a:
.zww...
~
V 3 Why is it important that the pieces of the metals are cleaned?

~
w

0
<D

Results

1 Complete the table as you carry out the experiment. [2]

Table 1

Positive terminal Negative terminal Voltage/ V

copper lead

copper magnesium

copper iron

copper zinc

copper tin

Conclusions [1]

1 Which combination of metals produces the greatest voltage?

2 Which combination of metals produces the smallest voltage? [1]

3 What do you think the voltage would have been if you had used a copper half-cell [1]
connected to both terminals of the voltmeter?

4 Which of the metals is the most reactive, and which is the least reactive (not including

copper)? [2]

5 Put the metals in order of reactivity with the least reactive first. [2]

76

6 For the most reactive metal, write an ionic half-equation to show what happens when it

is connected to the copper half-cell. [3] .m...

Evaluation [2] ~

How could the procedure have been improved to increase the reliability of the results? g-:,;I:,

Extension ::c

1 What do you think the voltage would have been if you had connected a lead half- sm:

cell to a magnesium half-cell to make an electrochemical cell? [2] ri

2 The experiment using the copper half-cell and the zinc half-cell was one of the first .).>..

made, and was called the Daniel cell. Use your research skills to find out about the (')

.mc.;.;.

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sm:

ri

.).>..

mz

m
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-C<l

0

.m...

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ri

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mz

m
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Cl

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Daniel cell and the voltage it produced. Was your voltage similar? If not, what could

have affected your value? [6]

77

MEETING 10. FUNDAMENTALS OF CHEMISTRY

BUILD A MOLECULE PHET SIMULATION - RECOGNIZING PATTERNS IN COVALENT BONDING

NAME_______________________________________________PERIOD________
BACKGROUND:
Most nonmetals form covalent bonds. These bonds involve shared valence electron pairs. Some atoms are only willing
to share a single electron pair – forming a covalent bond to only one other atom. Other atoms will bond to two, three or
even four other atoms at the same time. The purpose of this activity is to discover the pattern in the number of
covalent bonds various nonmetal atoms will form and to predict whether a molecule will contain a single covalent bond,
double covalent bond, or triple covalent bond.

TEST DRIVE THE SIMULATION:

OPEN THE SIMULATION: PhET – BUILD A MOLECULE, html 5 version.

● Use the “PLAYGROUND” mode for this activity.
● Experiment to see how the various buttons and controls work. Drag atoms together to form bonds.

Not a molecule – no Blue button –
name breaks bonds.

Molecule – name and Green button –
green 3D button shows 3D model
appear of molecule

Reset – move all Arrows to make
atoms back to Dishes different
combinations of
building atoms
available.

● Click on the 3D button of a finished molecule to see how the atoms are bonded.

3D View of molecule.

Use the ball and stick view for this lab. Each
“stick” represents a pair of shared
electrons/single covalent bond.

Touch here to display the ball and stick view.

This button can pause, or rotate the animated
model.

MEETING 10. FUNDAMENTALS OF CHEMISTRY

BUILD A MOLECULE PHET SIMULATION - RECOGNIZING PATTERNS IN COVALENT BONDING

NAME_______________________________________________PERIOD________

PART 1 – HOW MANY BONDS DO DIFFERENT ELEMENTS’ ATOMS FORM?

1. HYDROGEN: Drag two hydrogen atoms together. Fill in the chart for hydrogen below:

Formula: Name: 3D Ball and Stick Model Sketch:

H2

2. Try to drag a third hydrogen atom to the molecule you already have. Can you attach a third hydrogen to make
H3? _______________.

3. So based on this, we can conclude that a hydrogen atom only wants to bond to 1, 2, 3 (circle one) other atom.
4. Most nonmetals that form covalent bonds will form between 1 and 4 covalent bonds. Use hydrogen as a test

atom with the other atoms shown. See how many hydrogen atoms the other atoms will bond to in order to
form a stable molecule. For each, write the formula of the molecule, name the molecule, identify how many
covalent bonds (electron pairs) the atom will share, and sketch the ball and stick model of the molecule you
made. Use arrow keys to change elements as needed. Hydrogen is always one of the available elements for
molecule building.

Element bonded Formula of Name of Molecule Sketch of ball and Number of covalent
stick model bonds ELEMENT
to Hydrogen stable molecule forms

OXYGEN

CARBON

NITROGEN

CHLORINE

FLUORINE