C h a pt p t e r 9 : M a n u f a c t u r e d S u bs bs t a n c e s in In I n d us us t r y
The manufacture of sulphuric acid, H 2 2SO 4 4 through the Contact Process Stage 1: Combustion of Sulphur In the furnace, molten sulphur is burnt in dry air to produce sulphur dioxide, SO 2. The gas produced is purified and cooled. S(l) + O2(g) SO2(g) Stage 2: In the converter, sulphur dioxide, SO2 and excess oxygen gas, O2 are passed over a few plates of 0
vanadium (V) oxide, V2O5 catalyst at 450 C to produce sulphur trioxide, SO3. 2SO2(g) + O2(g)
Stage 3: In the absorber, the sulphur trioxide, SO 3 is first reacted with concentrated sulphuric sulphuric acid, H2SO4 to form a product called oleum, H2S2O7. SO3(g) + H2SO4(l) H2S2O7 The oleum, H2S2O7 is then diluted with water to produced concentrated sulphuric sulphuric acid, H2SO4 in large quantities. H2S2O7(l) + H2O(l) 2H2SO4(l) The two reactions in the third stage are equivalent to adding
2SO3(g)
About 99.5% of the sulphur dioxide, SO 2 is converted
sulphur trioxide, SO3 directly to water. SO3(g) + H2O(l) H2SO4(l)
into sulphur trioxide, SO3 through this reversible reaction.
Uses of Sulphuric Acid
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The manufacture of ammonia, NH 3 3 through the Haber
Process
1. Gases mixed and scrubbed
3. Converter
Haber process combines N2 gas from the air with
Then, it goes to the converter. It is then passed through layers of
H2 gas from natural gas to form NH 3.
iron catalyst with aluminium oxide as a promoter at a temperature
The two gases are mixed. The mixture is
of 450 C – 500 C
scrubbed to get rid of impurities.
4. Cooler
2. Compressor
A mixture of three gases leaves the converter. It is cooled until the
One volume of N2 gas and three volume of H2
ammonia condenses. The nitrogen and hydrogen are pumped
gas is compressed to a pressure of 200 – 500
back to the converter for another chance to react.
atm
5. storage tanks
N2(g) + 3H2(g)
2NH3(g)
0
0
NH3 is formed and then liquefy and separated to get a better yield. The NH3 is run into tanks and stored as a liquid under pressure.
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Metals
Alloys
-
Most metals are solid
-
Pure metals are made up of the same type of
-
atoms and are of the same size. -
composition in which the major components is a metal. -
The arrangement of the atoms in metals gives the
metals
their
ductile
and
malleable
The aim of making alloys is to make them stronger, harder, resistant to corrosion, have a better furnish and luster.
-
properties. -
A mixture of two or more elements with a certain fixed
The presence of atoms of other metals that are of different sizes disturb the orderly arrangement of atoms in the metal.
The orderly arrangement of atoms in metals
-
This reduces the layer of atoms from sliding.
enables the layers of atoms to slide on one
-
Thus, an alloy is stronger and harder than its pure metals.
another when force is applied. -
Thus, metals are ductile or can be stretched. Alloy Bronze
Brass
Steel
Composition
Properties
Uses
-
90% copper
-
Hard and strong
-
In building of statues or monuments
-
10% tin
-
Does not corrode easily
-
In the making of medals, swords and artistic
-
Has shiny surface
-
Harder than copper
-
70% copper
-
30% zinc
-
99% iron
-
1% carbon
materials. -
In the making of musical instruments and kitchenware
-
Hard and strong
-
In the construction of buildings and bridges
-
In the building of the body of cars and railways tracks
Stainless
-
74% iron
-
Shiny
-
In the making of cutlery
Steel
-
8% carbon
-
Strong
-
In the making of surgical instruments instruments
-
18% chromium
-
Does not rust
-
93% aluminium
-
Light
-
In the building of the body of aeroplanes
-
3% copper
-
Strong
-
3% magnesium
-
1% manganese
-
96% tin
-
Luster
-
3% copper
-
Shiny
-
1% antimony
-
Strong
Duralumin
Pewter
and bullet train
- In the making m aking of souvenirs
Polymers -
-
Synthetic Polymers
Polymers are large molecules made up of many
-
Synthetic polymers are man-made polymers.
identical repeating sub-units called monomers which
-
The monomers used are usually obtained from
are joined together by covalent bonds.
petroleum after going through the refining cracking
Monomers are joined into chains by a process of
processes.
repeated linking known as polymerization. -
A polymer may consists of thousands thousands of monomers. monomers.
-
Naturally occurring polymers: starch, cellulose, wool,
-
Examples:
polythene,
chloride
(PVC),
polypropene, perspex, nylon and terylene. -
protein. Silk and natural rubber
Synthetic polymers are very stable and do not corrode or decay, and also difficult to dispose.
-
They may cause pollution, blockage of drainage systems and flash floods.
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polyvinyl
3
Synthetic polymer Polythene
Monomer
Uses
Ethene
Plastic
bags, shopping shopping bags, plastic
containers containers and
insulation for electrical wiring Polypropene
Propene
Piping, bottle crates, carpets, car batteries and ropes
Polyvinyl chloride, chloride,
Chloroethene
Artificial Artifi cial leather, water pipes and records
Perspex Perspex
Methylmethacrylate Methylmethacrylate
Safety glass, glass, reflectors, traffic signs and lens
Terylene
Hexane-1,6-diol
Clothing, sails and ropes
PVC
Benzene-1,4-dicarboxylic acid Nylon
Hexane-1,6-diamine
Ropes, clothing and carpets.
Hexane-1,6-dioic Hexane-1,6-dioic acid Glass -
The major component of glass is silica or silicon dioxide, SiO 2 which found in sand.
-
Properties of glass: Transparent, hard but brittle, chemically inert, heat insulator, electrical insulator, impermeable to liquid -
-
Borosilicate glass (SiO2, Na2O, CaO, Al2O3, B2O3) Low thermal expansion coefficient Resistant to heat and chemical attack Hight melting point Uses Cooking utensuls, laboratory glassware, automobile headlights
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Fused glass (SiO2) Highly heat-resistant glass High transparency High melting point Resistant to chemical attack Uses Laboratory glassware, lenses, telescope, mirrors
-
Glass
-
Lead crystal glass (SiO2, Na2O, PbO, K2O, Al2O3) Soft abd easy to meltn High density High refractive index Uses Lead crystal glassware, art objects, lens, prisms and chandeliers
4
-
Soda-lime glass (SiO2, Na2O, CaO) Good chemical durability High thermal expansio e xpansion n coefficient Easy to make into different shapes Low melting point Uses Bottles, window panes, mirrors, electrical bulbs, flat glass and all kind of glass containers
Ceramics -
Ceramics are made from clay, for example kaolin, a hydrated aluminiumsilicate, Al 2O3.2SiO2.2H2O.
-
When the clay is heated to a very high temperature, they undergo a series of chemical reaction and are hardened permanently to form ceramics.
-
Ceramics are very hard, brittle, have a very high melting point, chemically inert and do not corrode.
-
The are good insulators of electricity and heat.
-
Uses of ceramics: construction materials – bricks, tiles, cement and pipes
-
Ornamental articles – bowls, cups, plates, vase and porcelain
-
Electrical insulators – spark plugs, fuses, insulators in electric iron and oven
-
Superconductors
Composite Materials -
Composite materials is a structural material that is formed by combining two or more different substance such as metal, alloys, glass, ceramics and polymers.
-
The resulting material has properties that are superior than those of the original components.
-
Composite materials are created for specific application. Composite
Component
Properties of
material
Properties Properti es of composite
Uses of composites
component
Reinforced
Concrete
concrete
Steel
-
Hard but brittle
-
Stronger
-
Construction of roads
-
Low tensile
-
Higher tensile strength
-
Rocket
strength
-
Does not corrode easily
Strong in tensile
-
Cheaper
strength
-
Can be moulded into any
-
-
Expensive
-
Can corrode
launching
pads -
High-rise buildings
-
Magnetically levitated
shape -
Can withsatand very high applied forces
-
Can support very heavy loads
Superconductor
-
-
-
Photochromic
Copper (II)
Insulators
oxide
electricity
of
-
Conducts Conducts electricity without resistance when cooled by
Tttrium
-
Transformers
oxide
-
Electric cable
Barium
-
Computer parts
oxide
-
Amplifier
-
Information
Glass
glass
liquid nitrogen
-
Transparent
-
Reduce refraction of light
-
Not sensitive to
-
Control the amount of light
light Silver chloride or
-
Sensitive light
to -
panels -
Light detector devices
automatically
-
Car windshields
Has the ability to change
-
Optical lens
silver
colour and become darker
bromide
when exposed to ultraviolet
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display
passes through it
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train
Fibre optics
Glass with
-
Transparent
-
Low material cost
low refraction
-
Does not reflect
-
Reflect light ray and allow
waves in
to travel along the fibre
telecommunications
index
light rays -
Instruments for
data or signals, voice and
examining internal parts
higher
images in a digital format,
of the body or inspecting
in the form of light along
the interiors of
the fine glass tubes at
manufactured structural
great speeds
products
index
Glass
-
High density
-
High tensile strength
-
Car bodies
-
Strong
-
Moulded and shaped
-
Helmets
brittle
-
Inert to chemicals
-
Skies
-
Non-flexible
-
Light
-
Rackets
Polyester
-
Light
-
Strong
-
Furniture
plastic
-
Flexible
-
Tough
-
Water storage tanks
-
Inflammable
-
Not inflammable
-
Small boats
-
Elastic
-
Impermeable to water
-
Resilient
-
Flexible
weak
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Transmit data using light
Glass with
refractive
Fibre glass
Can transmit electronic electronic
-
but
but
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