Uses Of Elements

Question 1

Chlorine (from sea water)

Answer 1

Sterilising drinking water and water in swimming pools

Manufacture of bleach
Manufacture of organic solvents
Manufacture of PVC

Question 2

Hydrogen (from sea water)

Answer 2

To make hydrochloric acid

As rocket fuel

Manufacture of Ammonia

Question 3

Sodium hydroxide solution (from sea water)

Answer 3

Manufacture of bleach / soaps / detergents / paper

Question 4

Nitrogen (from fractional distillation of liquefied air)

Answer 4

Manufacture of ammonia by the Haber process
Liquid nitrogen is used in cryogenics
Fill bags of potato chips to ensure the chips do not come into contact with oxygen.

Question 5

Oxygen (from fractional distillation of liquefied air)

Answer 5

-steel production to cast iron
-help patients with breathing difficulties

Question 6

Argon

Answer 6

-filling light bulbs

Question 7

Iron (metal)

Answer 7

-to build bridges

Question 8

Aluminium

Answer 8

-to make drink cans

Question 9

Copper

Answer 9

• make electric wires
• make cooking utensils

Question 10

Limestone

Answer 10

For construction of buildings and roads
Making glass (heat with sand and sodium carbonate)
Neutralising sulphur dioxide in flue gas from power stations
Neutralising acidity in soil and lakes
Make cement (heat with shale) —> make concrete (+sand+gravel+water)

Question 11

Quicklime

Answer 11

Making steel from iron
Neutralising the acidity of soil

Question 12

Slaked lime

Answer 12

Make bleaching powder
Neutralising the acidity of soil and lakes

Question 13

Silicon (semi-metal)

Answer 13

• a semi-conductor in solid-state devices in the computer and microelectronics industries.

Question 14

Graphite (a form of carbon)

Answer 14

Only weak van der Waals’ forces exist between the layers of carbon atoms, so that layers can slide past each other easily. This makes graphite a soft material that feel slippery to the touch.
1. As a lubricant: solid lubricant since he layers of carbon atoms can slide past each other easily.
2. Pencil ‘leads’: graphite (mixed with clay) is used in pencil ‘leads’. As you move a pencil across a piece of paper, layers of carbon atoms flake off the structure, so pencil marks appear on the paper. (Layers: weak van der Waals’ force
3. Electrical conductivity: it is a non-metal that conduct electricity well. The presence of delocalised electrons along the layers allows graphite to conduct electricity when a voltage is applied. Graphite is also used to make a brushes in electric motors and electrodes in dry cells.