Sulphuric acid

1. Sulphuric acid is manufactured in industry through the Contact Process. There are three stages in the Contact Process.

Stage 1: Production of sulphur dioxide from sulphur

Stage 2: Production of sulphur trioxide from sulphur dioxide at temperature of

               450-500 ^oC ,  pressure of 2 - 3 atmospheres. The catalyst used is

              vanadium (V) oxide (optimum condition)

Stage 3: Conversion of sulphur trioxide to sulphuric acid

Ammonia and Its Salts

1. Ammonia is manufactured on a large scale in the Haber process where nitrogen and hydrogen gases are mixed in the ration of 1:3. The mixture is passed over an iron catalyst under the controlled optimum condition of 450-500 ^oC and pressure of 200 – 500 atmospheres.

N₂ (g) + 3H(g)à 2NH₃ (g)

        ß

2. Reaction of ammonia with acids produces ammonia salts such ammonia sulphate which is used as fertilizers

Alloys

1. An alloy is a mixture of two or more metals (sometimes non-metal) in a specific proportion. The added metals are usually in small mounts.
2. The purposes of making alloys are to increase the strength of metals, to improve the resistance to corrosion and to enhance the appearance.

Synthetic Polymers

1. Molecules that consist of a large number of small identical units joined together repeatedly are called polymers. The smaller molecules that make up the repeating units is polymers are called monomers
2. The process joining together  a large number of small molecules to form polymers is called polymerisation
3. Synthetic polymers are toiler-made with specific properties to suit the demand of our modern life. Polyethene are used to make plastic bags and films for wrapping food and vegetable whereas PVC is used to make insulating material and water pipes.

Glass and Ceramics

1. The main components of glass are silicon dioxide, SO₂, which exits naturally in sand. Other components like sodium oxide, calcium oxide , boron oxide and other are aged to change the properties of the glass
2. The compositions of glass are tailors to produce different types of class with their specific properties to suit different uses. The common glasses are fused glass, soda-lime glass, borosilicate glass and lead crystal glass.
3. Traditional silicate ceramics are made by heating aluminosilicate clay such as kaolin to a very high temperature. Modern ceramic material comes in a variety of form. They include oxide ceramic , such as alumina (Al₂O₃) non –oxide ceramic such as silicon carbide (SiC) and silicon nitride (Si₃N₄)

Composite Materials

1. Two or more different substance is mixed and combined together to create a new material which has more improved qualities over the original components. The new substance is called a composite material or composite.
2. Some common composite materials are reinforced concrete, superconductor, fiber optics, fiber glass and photochromic glass.

EXERCISE

1. What is an alloy?
2. Name two alloy, its composition and state its uses
3. Using the arrangement of the atom, explain why an alloy is harder than the pure metal.
4. Alloying iron can prevent it from corrosion. Describe how you can use another method other than alloying, to prevent the corrosion of the iron.