chemistry booklettt

Chapter 8:





Manufactured Substances








In Industry

INDEX


Chapter 8: Manufactured Substances in Industry





Subtopic Title Page




8.1 Alloy and Its Importance 1 - 5







-



8.2 Composition of Glass 7


6
and Its uses


8.3 Composition of Ceramics 8 - 9
and Its Uses






8.4 Composite Materials and 10 - 17
Its Importance







Students and their assigned subtopics:

8.1 - Sarvini and Dhanush

8.2 - Eron


8.3 - Ovena

8.4 - Theresa, Lalitha, Waheida and Yoga

8.1 Alloy and Its Importance


What is an alloy?

~ A mixture of two or more elements where the main element is a metal.




Examples of an alloy and its uses :-
Pewter - Used to make souvenirs.

Duralumin - Used to make the body of an aeroplane.

Bronze - Used to make medals.

Brass - Used to make keys.

Steel - Used to make the body of a car.

Stainless steel - Used to make cutlery.



Comparison of Properties of Alloy and Pure Metals





ALLOY Pure metal



Shiny Surface Dull



Resistant to corrosion Resistance to Easily corroded
corrosion

Hard Hardness Less hard

~ A pure metal is made
up of one type of atom
that is of the same size
and arranged in an
orderly arrangement.

~ When force is applied,
the layers of atoms in
the metal easily slide
over each other.







~ Pure metals are also
malleable and its shape
can be easily changed.

~ There are empty
spaces between the
atoms in pure metals.

~ When force is applied,
the layer of atoms in a
metal will slide to fill
the empty spaces and
form a new structure.






~ An alloy is formed
when foreign atoms are
mixed with the pure
metal.

~ These foreign atoms
are different in size
compared to the atoms in
the pure metals.

~ The orderly
arrangement of atoms
in a pure metal is
disrupted.

~ This makes it difficult
for the layers of atoms in
alloy to slide over each
other when force is
applied.

8.1 Justify The Uses of Alloys Based on Their Composition and Properties.

1) Duralumin

Composition

• 93% Aluminium
• 3% Copper
• 3% Magnesium
• 1% Manganese
Properties


• Stronger than pure aluminium
• Low density
• Does not rust
Uses

• Body of aeroplanes
• Electric cables
• Racing bicycles



2) Bronze

Composition

• 90% Copper
• 10% Tin

Properties

• Stronger than pure copper
• Does not rust
• Shiny

Uses

• Medals
• Monuments
• Trophies

3) Brass

Composition

• 70% Copper
• 30% Zinc

Properties

• Stronger than pure copper
• Does not rust
• Shiny

Uses
• Musical instruments
• Doorknobs
• Keys



4) Steel

Composition

• 98% Iron
• 0.2 – 2% Carbon

Properties

• Also known as carbon steel
• Stronger and harder
• Malleable
• Three types of steel, low-carbon, average-carbon and high-carbon steel
Uses


• Structure of buildings
• Railway tracks
• Body of cars


5) Stainless Steel

Composition

• 73% Iron
• 18% Chromium
• 8% Nickel

• 1% Carbon

Properties

• Stronger to pure iron
• Resistant to corrosion

Uses

• Cutlery
• Sinks
• Surgical instruments


6) Pewter

Composition

• 95% Tin
• 3.5% Antimony
• 1.5% Copper

Properties

• Stronger than pure tin
• Does not rust
• Shiny

Uses

• Decorative ornaments
• Trophies
• Souvenir

Chapter 8.2 Composition Of Glass And Its Uses






Basic Properties Of Glass
-Hard but brittle -Chemically inert

-Transparent -Waterproof

-Heat insulator -Electrical insulator

Types Of Glass

1) Fused silica glass (Silica dioxide only)




















-1800 Celcius to melt

-Does not expand,contract when there is large change in temperature

-Telescope lens




2) Soda-lime glass (Silica + Sodium carbonate + Calcium carbonate)



















-Soda lowers the melting point of silica, hence it has low melting point 1000 Celcius

-Easily moulded

-Cannot withstand high temperature and cracks easily with sudden temperature change

-Glass containers

3) Borosilicate glass (Silica + Sodium carbonate + Calcium carbonate + Boron oxide +
Aluminium oxide)

























-Heat resistant

-Do not crack easily when subjected to thermal pressure

-Low expansion coefficient

-Laboratory glasswares




4) Lead crystal glass (Silica + Sodium carbonate + Lead (II) oxide)

























-Lead replaces calcium to make glass softer and denser

-Heavier

-High refractive index

-Prism

8.3 Composition of Ceramics and Its Uses


What is a ceramic?

- A solid made up of inorganic and non-metallic substances.

- It is produced through the process of shaping and hardening by using heating technique
at a high temperature.



Examples of ceramic:


















Aluminium Oxide Titanium carbide Silicon carbide






Basic properties of ceramics

✓ High thermal resistant
✓ Break easily
✓ Chemically inert
✓ Electrical insulator
✓ Hard and Strong
✓ Heat insulator




The atoms in ceramics are bonded by strong covalent bonds and ionic bonds

Ceramics melt at only very high temperature, are hard and resistant to temperature.



The electrons in ceramics cannot move freely to conduct electricity or heat


Ceramics are brittle and weak towards stretching.

Types of ceramics:


Traditional ceramics

- Made of clay such as kaolin
- The clay is mixed with water to produce a soft,
mouldable mixture.

- The mixture is then heated at a very high
temperature.
- Examples of traditional ceramics: Pottery, Brick
and Bowl.



Advanced ceramics

- Made from inorganic compounds such as
oxides, carbides and nitrides.

- Have higher resistant to heat and abrasion.

- More chemically inert and have
superconductivity properties.

- Examples of advanced ceramics: Cutting disc,
Brake disc and Tungsten carbide ring.



Examples of ceramic uses:


- Zirconia ceramic is used in dental implants
- Alumina ceramic is used to make knee bone
Medicine - Ceramic is used in Magnetic Resonance Imagining (MRI) machines
because it has superconductivity properties

- Engine components is jet planes are made from ceramics
Transportation


- Ceramic is used to make electrical insulators in high voltage areas
Energy such as power stations
production

8.4 COMPOSITE MATERIALS AND ITS IMPORTANCE





A composite material is a material made from
combining two or more non-homogeneous

substances :-

1) Matrix Substance

2) Strengthening Substance

*Matrix substance surrounds and binds the

strengthening substance together.

COMPOSITE MATERIALS AND THEIR USES







1) Reinforced concrete is produced when steel bars or
wire mesh (strengthening substance) is immersed in

concrete (matrix substance).























2) Fibre glass is produced when plastic (matrix
substance) is strengthen with glass fibres (strengthening
substance).

Optical fibre





THE INNERMOST LAYER IS THE CORE THAT IS MADE UP OF SILICA


GLASS FIBRES(STRENGTHENING SUBSTANCE).THE CORE IS
ENCASED IN A SECOND LAYER OR CLADDING THAT MADE UP OF


GLASS OR PLASTIC (MATRIX SUBSTANCE).THE OUTERMOST LAYER

IS MADE UP OF PLASTIC THAT ACTS AS PROTECTIVE

JACKET(MATRIX SUBSTANCE).OPTICAL FIBRES ARE USED TO

TRANSMIT INFORMATION AND DATA IN THE FORM OF LIGHT.THE

CORE AND CLADDING HAVE DIFFERENT REFRACTIVE INDEXES TO

ENABLE THEM TO CARRY DATA IN LARGE CAPACITY AND NOT TO
BE INFLUENCED BY ELECTROMAGNETIC DISTURBANCES.



EXAMPLE:

PHOTOCHROMIC GLASS


Formed when glass (matrix substance) is combined with

silver chloride,AgCl and copper(I) chloride,CuCl

(strengthening substance).When exposed to

sunlight,photochromic glass darkness.This is due to the

formation of silver atoms,Ag that prevents the passage of

light.In dim light, copper(I) chloride ,CuCl in the


photochromic glass catalyses the reverse process so that
glass becomes transparent again. EXAMPLE:

SUPERCONDUCTORS


Yttrium barium copper oxide, YBCO ceramic is a

composite material that has superconductivity properties

other than alloys.This superconductor is used to make

electromagnets,that are superconductor magnets or

supermagnets.Superconducter magnets are light and have

strong magnetic force. EXAMPLE:

COMPARISON AND DIFFERENCE IN PROPERTIES OF COMPOSITE
MATERIALS AND THEIR ORIGINAL COMPONENTS



Composite materials have different properties compared to their original components.


Concrete
⁂ withstand high compression forces

⁂ breaks if subjected to high stretching forces
⁂ Combination of concrete and steel bars or wire mesh can increase the ability of the
concrete to withstand compression forces















Plastic matrix consists of plastic that is weak, soft and easily burned. The properties of plastic
are reinforced by adding glass fibres.





















Optical fibre has high compression strength although the original component that is glass
fibre, is brittle.

PROPERTIES
-Transparent to visible light
Silver Chloride -Absorb UV rays
- sensitive to light intensity
PHOTOCHROMIC
GLASS
PROPERTIES
Glass - Transparent
-Doesnt absorb UV rays
- Not sensitive to light














PROPERTIES
- Transparent

-Absorbs UV rays
- The absorption of UVb rays depends
on light intensity





8.14 Comparison in properties of photochromic glass with its original component

PROPERTY

High electrical resistance at
room temperature










Barium
carbonate



Copper(II)
carbonate



Superconductor

(YBCO)





Yttrium(III)
carbonate



Oxygen PROPERTY

-No electrical resistance at
very low temperature




8.15 Comparison in properties of superconductor with its original components