CHEMISTRY FORM 4: CHAPTER 8

TOPIC: MANUFACTURED SUBSTANCE IN
INDUSTRY

NAME: ‘AQILAH NUR BINTI GHAZALI
CLASS: 4DLP
TEACHER: PN SITI ASIAH
SCHOOL: SMK BANDAR BARU UDA

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

Pewter Duralumin

Stainless steel Alloy Bronze

Steel Brass

Comparison of Properties of Alloys and Pure Metals:

Strength and hardness of alloys are based on the arrangement of
particles.

Alloy Pure metal

Shiny Surface Dull

Resistant to corrosion Resistance Easily corroded
Hard to Less hard

corrosion

Hardness

Pure metals are ductile:

*Made up of one type of atom of the same size.
*Arranged in an orderly arrangement.
*Layers of atoms in the metal slide over each other easily when force is
applied.
*Causing pure metals to be ductile and pulled into fine wires easily.

Pure metals are malleable:

*Its shape can be changed easily.
*There are empty space between atoms in a pure metal.
*The layers of atoms in a metal will slide to fill empty spaces and form a
new structure when force is applied.

Arrangement of atoms in an alloy:

*Formed when foreign atoms are mixed with the pure metal.
*Foreign atoms have different sizes compared to atoms in pure metal.
*The orderly arrangement of atoms in a pure metal is disrupted.
*Layers of atoms in an alloy are difficult to slide over each other when
force is applied.

Justify the Uses of Alloys based on Their Composition and
Properties

Alloy Composition Properties Uses

Duralumin *93% Aluminium *Stronger than pure *Body of
*3% Copper Aluminium. aeroplanes
Bronze *3% Magnesium *Low density *Electric cables.
*1% Manganese *Doesn’t rust *Racing bicycles.
*Stronger than pure *Medals
*90% Copper copper *Monuments
*10% Tin *Doesn’t rust. *Trophies
*Shiny
Brass *70% Bronze *Stronger than pure *Musical
*30% Zinc copper instruments
*Doesn’t rust *Doorknobs
Steel *98% Iron *Shiny *Keys
*0.2-2% Carbon *Known as carbon steel. *Structure of
*Stronger and harder buildings
Stainless steel *73% Iron *Malleable *Railway tracks
Pewter *18% Chromium *Types: low-carbon *Body of cars
*8% Nickel steel, average-carbon
*1% Carbon steel, high-carbon steel *Cutlery
*Stronger than pure iron *Sinks
*95% Tin *Resistant to corrosion *Surgical
*3.5% Antimony instruments
*1.5% Copper *Stronger than pure tin *Decorative
*Doesn’t rust ornaments
*Shiny *Trophies
*Sourvenirs

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

Hard but Chemically
brittle inert

Electrical Basic Transparent
insulator properties
of glass

Heat insulator Waterproof

Types of glass

*Made from silica (silicon dioxide, SiO2 )
*Melt around 1800 oC, high melting point.
*Doesn’t expand/ contract much when temperature change drastically.
*e.g= telescope lens.

*Made from silica, SiO2, soda(sodium carbonate, Na2CO3) and
limestone(calcium carbonate, CaCO3).
*Soda, NaCO3 lowers melting point of silica, SiO2.
*Has low melting point, 1000 oC.
*Easily moulded and used to make glass containers (bottles and jugs)
*Can’t withstand high temperatures, easily crack when subjected to
sudden temperature change.

*Made from silica, SiO2, soda, Na2CO3, limestone, CaCO3, boron oxide,
B2O3 and aluminium oxide, Al2O3.
*Lots of laboratory glassware made from borosilicate glass because its
resistant to heat.
*Doesn’t crack easily when subjected to thermal stress due to its low
expansion coefficient.
*Can be removed from refrigerator and heated immediately without
cracking.

*Made from silica, SiO2, soda, Na2CO3 and lead(II) oxide, PbO.
*Pb replace calcium, Ca to produce glass that’s softer and denser.
*Heavier and has high refractive index.
*Suitable in making prisms.

Ceramic: A solid made up of inorganic and non-metallic substances.
*Produced through the process of shaping and hardening by using
heating technique at a high temperature.

Hard and High
strong thermal
resistant

Electrical Basic Break
insulator properties easily

of
ceramics

Heat Chemically
insulator inert

*Atoms are bonded by strong covalent bonds and ionic bonds.
*Melt at high temperature, high melting point.
*Hard and resistant to compression.
*When force applied:
**Atoms cannot slide over each other because strongly bonded in

indefinite arrangement.
**Energy from force will be used to break the bonds between atoms.
**Causing ceramics brittle and weak towards stretching.
*Electrons in ceramics cannot move freely to conduct electricity or heat.

Types of Ceramics:

*Made from clay such as kaolin, Al2O3.2SiO2.2H2O
*Clay mixed with water to produce a soft, mouldable mixture.
*Mixture then heated at scorching temperature.
*Generally used to make bricks, pottery and crockery.

*Made from inorganic compounds such as oxides, carbides and nitrides.
*Have higher heat resistance and abrasion.
*More chemically inert, have superconductivity properties.
*Silicon carbide functions:
**Used to make cutting disc[hard and strong properties]
**Make brake disc because it can withstand thermal shock and has high

resistance to heat.

Ceramic Uses Application

Medicine *Zirconia ceramic[dental implants]
*Alumina ceramic[Knee bone making]
Transportation *Ceramic[Magnetic Resonance Imaging, MRI
Energy machine due to its superconductivity properties]
production
*Engine components in jet planes.

*Electric insulator in high voltage areas[power
stations]

*Composite material: A material made from combining two or more non-
homogeneous substance
*Matrix substance and strengthening substance.
*Matrix substance surrounds and binds the strengthening substance
together.
*Both components have different physical and chemical properties.
*When combined, composite material formed has better properties
than original components.

Composite Materials and Their Uses

*Steel bars or wire mesh is immersed in concrete.
*Widely used in bridge construction, dams, buildings.

*Plastic is strengthened with glass fibre.
*Helmets, car bumpers and printed circuit boards.

*Consist three layers.
*Innermost layer is the core, made from silica glass fibres.
*Core is encased in second layer or cladding, made up of glass or plastic.
*Outermost layer is made of plastic, acts as a protective jacket.
*Used to transmit information and data in the form of light.
*Light moves through the optical fibre(core section).
*Core and cladding have different refractive indexes.
*Has replaced copper wires in video cameras and connects computers in
LAN.

*Glass is combined with silver chloride, AgCl and copper(I) chloride,
CuCl.
*When exposed to light:
**Photochromic glass darkens.
**Formation of silver atoms, Ag that prevents passage of light.
*In dim light:
**CuCl in photochromic glass catalyses the reverse process so that glass
becomes transparent again
*Protects the user from UV rays.
*Suitable for car windows, camera lenses, building windows.

*Yttrium barium copper oxide, YBCO, Has superconductivity
properties other than alloy.
*Superconductor magnets [Supermagnets]:
**Light and have strong magnetic force.
**e.g= Particle accelerator, Nuclear Magnetic Resonance(NMR) machine,

Magnetic Resonance Imaging(MRI) machines.

Comparison and Difference in properties of
Composite Materials and Their Original Components

Properties
*High compression strength
*Low stretching strength
*Resistant to corrosion

Properties
*High stretching strength
*Corroded easily

Properties:
*Low stretching strength
*Low heat and electrical
conductivity
*Resistant to corrosion
*Durable

Properties
*High stretching strength
*Low heat and electrical
conductivity

Properties
*High compression strength
*Flexible

Properties
*Low compression strength
*Hard

Properties
*Transparent
*Does not absorb UV rays
*Not sensitive to light

Properties
*Transparent to visible light
*Absorb UV rays
*Sensitive to light intensity

Properties
High electrical resistance at
room temperature