CHEMISTRY: CHAPTER 8

Name: Ezra Daniesa Binti ABD Rasid
Class: 4 DLP

Subject: Chemistry

Topic: Manufactured Subtances In Industry

8.1 Alloy And Its Importance

What is Alloy?

→ Alloy is a mixture of two or more elements where the main element is a metal.

Alloy

Duralumin Bronze Pewter Steel Stainless Brass
Steel

Comparison Between Alloy And Pure Metal

Alloy Pure Metal

Shiny Surface Dull

Resistant to Resistance to Easily corroded
corrosion Corrosion

Hard Hardness Less hard

Pure Metal Are Ductile

→ Made up of one type of atom that is of the same size and arranged in orderly
arrangement.
→ Force applied:

→ layers of atom is easily slide over each other.
→ Causes the pure metal to be ductile, easily pulled into fine wires.

Pure Metals Are Malleable

→ Its shape can be easily changes.
→ Have empty spaces between atoms.
→ Force applied:

→ Layers of atom will slide to fill the empty spaces.
→ Easily form a new structures.

Arrangement of Atoms In An Alloy

→ Foreign atom is mixed with pure metal.
→ Different size of foreign atoms.

→ Orderly arrangement of atoms in pure metal is disrupted (force is applied).
→ Makes it difficult for atoms to slide over each other.

Uses of Alloy Based On Their Composition And Properties

Alloy Composition Properties Uses
Duralumin - 93% Aluminium - Stronger than pure - Body of aeroplanes
- 3% Copper aluminium - Electric cables
Bronze - 3% Magnesium - Low density - Racing bicycles
Brass - 1% Manganese - Does not rust
Steel - 90% Copper - Stronger than pure copper - Medals
- 10% Tin - Does not rust - Monuments
- Shiny - Trophies
- 70% Copper - Stronger than pure copper - Musical instruments
- 30% Zinc - Does not rust - Doorknobs
- Shiny - Keys
- 98% Iron - Also known as carbon steel - Structure of buildings
- 0.2 – 2% Carbon - Stronger and harder - Railways tracks
- Malleable - Body of cars
Stainless Steel -73% Iron - There are three types of
Pewter - 18% Chromium steel; low-carbon steel, - Cutlery
- 8% Nickel average-carbon steel and - Sinks
- 1% Carbon high-carbon steel - Surgical instruments
- 95% Tin - Stronger than pure iron
- 3.5% Antimony - Resistant to corrosion
- 1.5% Copper
- Stronger than pure tin - Decorative ornaments
- Does not rust - Trophies
- Shiny - Souvenirs

8.2 Composition Of Glass And Its Uses

What is Glass?

→ When silica is heated together with other chemicals, various types of glass with different
properties are obtained.

Electrical Hard but Chemically
Insulator brittle inert

Heat Basic Properties Transparent
Insulator of Glass

Waterproof

Types Of Glass
Fused Silica Glass

→ Made from silica (Silicon Dioxide, SiO2)
→ High melting point (1800℃).
→ Does not expand / contract in a change of temperature.
→ Examples; Telescope lens.

Soda-lime Glass

→ Made from silica (Silicon Dioxide, SiO2), soda (Sodium Carbonate,
Na2CO3) and limestone (Calcium Carbonate, CaCO3).

→ Soda, Na2CO3, lowers the melting point of silica, SiO2.
→ Low melting point (1000℃)

→ Easily moulded
→ Cannot withstand high temperature
→ Easily crack
→ Example; Glass containers such as bottles and jugs.

Borosilicate Glass

→ Made from silica, SiO2, soda, Na2CO3, limestone, CaCO3, boron oxide, B2O3 and
aluminium oxide, Al2O3

→ Resistance to heat.
→ Do not crack easily when subjected to thermal stress;

→ Low expansion coefficient.
→ Can be removed from refrigerator and heated immediately.
→ Example; Beakers and flasks .

Lead Crystal Glass

→ Made from silica, SiO2, soda, Na2CO3 and lead (II) Oxide, PbO
→ Lead, Pb replaces calcium, Ca
→ Produce softer and denser glass.
→ Heavier.
→ High refractive index.
→ Example; Prisms.

8.3 Composition Of Ceramics And Its Uses

What is Ceramics?

→ Ceramics is a solid made up of inorganic and non-metallic substances.
→ Produced through shaping and hardening process using heating technique at a high
temperature.
→ Example; Aluminium oxide, Al2CO3, Titanium Carbide, TiC, Silicon Carbide, SiC

Basic Properties Of Ceramics

→ Atoms bonded by strong covalent bond ionic bond.
→ High melting point and atoms cannot move freely to conduct heat / electricity.
→ Hard and resistant to compression.
→ Force applied;

→ Atoms cannot force over each other.
→ Strongly bonded in indefinite arrangement.
→ Force’s energy used to break the bonds between atoms.
→ Brittle and weak towards stretching.

High
thermal
resistant

Heat Break
insulator easily

Hard and Basic
strong Properties

Chemically
inert

Electrical
insulator

Types Of Ceramics
Traditional Ceramics

→ Made from clay.
→ The clay is mixed with water to produce soft and mouldable mixture.
→ The mixture is heated at a very high temperature.
→ Example; Bricks, kaolin, pottery and crockery.

Advanced Ceramics

→ Made from inorganic compounds (oxides, carbides and nitrides).
→ Higher resistance to heat and abarasion.
→ More chemically inert.
→ Hace superconductivity properties.
→ Example; Silicon Carbides and Tungsten Carbides Ring.

Ceramic Uses Application

Examples Medicine - Zirconis ceramic is used in dental implants
of ceramic - Aluminia ceramic is used to make knee bone
- Ceramic is used in Magnetic Resonance Imaging
uses (MRI) machines because it has supercoductivity
properties
Transportation - Engine components in jet planes are made from
Energy Production ceramics
- Ceramic is used to make electrical insulators in
high voltage areas such as power stations

8.4 Composite Materials And Its Importance

What is Composite Materials?

→ Material made combining two or more non-homogeneous substances (matrix substances
(MS) and strenghtening substances (SS)).
→ Matrix substances surround and bind the strengthening substance.
→ Example; Lignin (MS) + Cellulose Fibers (SS) → Wood (Composite Material).

Composite Material And Its Uses
Reinforced Concrete

→ Steel bars / wire mash (SS) is immersed in concrete (MS).
→ Example; Bridges, dams and buildings.

Fibre Glass

→ Plastic (MS) is strengthened with glass fibre (SS).
→ Example; Helmets, car bumpers and printed circuit boards.

Optical Fibre

→ Innermost Layers;
→ Made up of silica glass fibres (SS).

→ Second Layers / Cladding;
→ Made up of glass / plastic (MS).

→ Outermost Layers;
→ Made up of plastic acts as protective jacket (MS).

→ Transmit information and data in the form of light.
→ Light moves through optical fibre (core section).

→ The core and cladding have different refractive indexes.
→ Enable to carry data in large capacity.
→ Not influenced by electromagnetics disturbances.

Photochromic Glass

→ Glass (MS) is combined with Silver Chloride, AgCl and Copper Chloride, CuCl2 (SS).
→ Expose to sunlight;

→ Photochromic glass will darkens.
→ Formation of silver atoms, Ag, prevents the passage of light.

→ In dim light;
→ CuCl2 in photochromic glass catalyses the reverse process, glass becomes transparent.

→ Protects the user from UV rays.
→ Example; Car windows and camera lenses.

Superconductors

→ Has superconductivity properties such as Yttrium Barium Copper Oxide, YBCO.
→ Used to make electromagnets.
→ Superconductor magnet;

→ Light
→ Strong magnetic force
→ Example; Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging
(MRI)

Comparison And Difference In Properties Of Composite Materials And Their
Original Components

Reinforced Concrete

Concrete Reinforced Concrete

- High compression strength - High compression strength
- Low stretching strength - High stretching strength
- Resistant to corrosion - Resistant to corrosion

Steel bars / Wire mash

- High stretching strength

- Corrodes easily

Fibre Glass Fibre Glass
- High stretching strength
Plastic - Heat and electrical insulator
- Low stretching strength - Resistant to corossion
- Low heat and electrical conductivity
- Resistant to corrosion - Durable

- Durable

Glass Fibre
- High stretching strength
- Low heat and electrical conductivity

Optical Fibre Optical Fibre
- High compression strength
Plastic
- High compression strength - Flexible

- Flexible Photochromic Glass
- Transparent
Glass Fibre
- Low compression strength - Absorb UV rays
- The absroption of UV rays depends on
- Hard
light intensity
Photochromic Glass
Superconductor (YBCO)
Glass - No electrical resistance at
- Transparent
- Does not absorb UV rays very low temperature
- Not sensitive to light

Silver Chloride
- Transparent to visible light

- Absorb UV rays
- sensitive to light intrensity

Superconductors

Yttrium (II) Carbonate + Copper (II)
Carbonate + Barium Carbonate +
Oxygen
- High electrical resistance at room
temperature

The End