Manufacturing Of Products

Question 0

Diaphragm

Answer 0

Necessary to keep apart sodium hydroxide and chlorine so they don’t make bleach

Question 1

Manufacturing of sodium hydroxide

Answer 1

Manufactured by the electrolysis of a concentrated solution of sodium chloride. Hydrogen is a by product

+anode: chlorine loses electrons, chlorine molecules formed

-cathode: water molecules gain electrons, hydroxide ions and hydrogen molecules formed

Question 2

Uses of sodium hydroxide

Answer 2

Manufacture of

Bleach, paper, soap, detergents

Question 3

Uses of chlorine

Answer 3

Sterilising water supplies
Manufacture of:
Bleach, hydrochloride acid, PVC

Question 4

Stages of sulphuric acid manufacture

Answer 4

Sulfur dioxide -> burning sulfur in air
Sulfur trioxide -> sulfur dioxide reacted with oxygen
Oleum -> sulfur trioxide absorbed into concentrated sulfuric acid
Sulfuric acid -> Oleum carefully diluted

Question 5

Manufacturing sulfuric acid exras

Answer 5

Vanadium oxide catalyst
Reversible reaction
Position of equilibrium
Forward action is exothermic
Yield of sulfur trioxide high at low temperatures but very slow
450*C compromise
Yield is high at low pressures so not economical to go higher

Question 6

Manufacture of sulfuric acid

Answer 6

Air + sulfur dioxide -> mixture of gases is cleaned by electrostatic precipitation (400-500*C) (2 atmospheres)

Mixture of gases passed over vanadium oxide catalyst
Oxygen combined with carbon dioxide to form sulfur trioxide
-98% yield

• > unreacted gases recycled
• —>sulfur trioxide dissolved in concentrated sulfuric acid -> oleum

Oleum acts with water forming sulfuric acid

Question 7

Sulfuric acid uses

Answer 7

Manufacture of detergents
Manufacture of fertilisers
Manufacture of paints

Question 8

Manufacture of ammonia

Answer 8

Nitrogen(air) + hydrogen (natural gas, cracking)

Reaction is reversible, can reach an equilibrium (shift to right, high yield of ammonia)

Low temperature, high pressure (compromise of 450*C or to slow)

Very high pressures (200 atmospheres) -> expensive
(energy required, container, thick walled pipes)

Question 9

Manufacture of ammonia general

Answer 9

Catalyst used : many metals will work
Most economical is iron

Only 15% of hydrogen and nitrogen converted to ammonia

Question 10

Uses of ammonia

Answer 10

Manufacture of:

Fertilisers, nitric acid, nylon