2f sulphur and nitrogen. allotropes of sulphur sulphur molecule consists of 8 atoms in a ring form

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2f Sulphur and Nitrogen

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Page 1: 2f Sulphur and Nitrogen. Allotropes of sulphur Sulphur molecule consists of 8 atoms in a ring form

2f Sulphur and Nitrogen

Page 2: 2f Sulphur and Nitrogen. Allotropes of sulphur Sulphur molecule consists of 8 atoms in a ring form

Allotropes of sulphur

Sulphur molecule consists of 8 atoms in a ring form.

Page 3: 2f Sulphur and Nitrogen. Allotropes of sulphur Sulphur molecule consists of 8 atoms in a ring form

Allotropes of sulphur

It melts at 115°C (low) which is because of its simple molecular structure.

Page 4: 2f Sulphur and Nitrogen. Allotropes of sulphur Sulphur molecule consists of 8 atoms in a ring form

Allotropes of sulphur

At first the sulphur is very runny because of the weak bonds between the sulphur molecules (intramolecular bonds)

Page 5: 2f Sulphur and Nitrogen. Allotropes of sulphur Sulphur molecule consists of 8 atoms in a ring form

Allotropes of sulphur

As it is heated more strongly, the rings break and join together to make long chains. It becomes sticky.

Page 6: 2f Sulphur and Nitrogen. Allotropes of sulphur Sulphur molecule consists of 8 atoms in a ring form

Allotropes of sulphur

Near to the boiling point, the chains start to break, the liquid is less viscous and it starts to evaporate.

Page 7: 2f Sulphur and Nitrogen. Allotropes of sulphur Sulphur molecule consists of 8 atoms in a ring form

Allotropes of sulphur

When it evaporates it forms S2 molecules (like O2 which is also group 6)

Page 8: 2f Sulphur and Nitrogen. Allotropes of sulphur Sulphur molecule consists of 8 atoms in a ring form

Allotropes of sulphur

If it is poured quickly into water, plastic sulphur is made.It is “frozen” in long chain molecules like rubber.

Page 9: 2f Sulphur and Nitrogen. Allotropes of sulphur Sulphur molecule consists of 8 atoms in a ring form

Allotropes of sulphur

It will eventually change back into S8.

Page 10: 2f Sulphur and Nitrogen. Allotropes of sulphur Sulphur molecule consists of 8 atoms in a ring form

Nitrogen

• Extracted from air by fractional distillation

• If air is cooled down, at -183°C oxygen condenses into a liquid and then at -196°C Nitrogen condenses too.

Page 11: 2f Sulphur and Nitrogen. Allotropes of sulphur Sulphur molecule consists of 8 atoms in a ring form

Nitrogen

Nitrogen is generally an unreactive gas, and needs fairly extreme conditions to get it to react with oxygen

Its inert nature is used to help preserve food.

Page 12: 2f Sulphur and Nitrogen. Allotropes of sulphur Sulphur molecule consists of 8 atoms in a ring form

Ammonia NH3

Page 13: 2f Sulphur and Nitrogen. Allotropes of sulphur Sulphur molecule consists of 8 atoms in a ring form

Ammonia NH3

Page 14: 2f Sulphur and Nitrogen. Allotropes of sulphur Sulphur molecule consists of 8 atoms in a ring form

Ammonia NH3

• Only common alkaline gas Only common alkaline gas.

• EASILY dissolves in water

• Turns damp litmus paper blue.

Page 15: 2f Sulphur and Nitrogen. Allotropes of sulphur Sulphur molecule consists of 8 atoms in a ring form

Laboratory preparation of NH3

• Heat solid ammonium chloride with solid calcium hydroxide

Page 16: 2f Sulphur and Nitrogen. Allotropes of sulphur Sulphur molecule consists of 8 atoms in a ring form

Ammonia + acids

• Ammonia (an alkali) reats with acids to form salts

NH3 + HNO3 NH4NO3

Page 17: 2f Sulphur and Nitrogen. Allotropes of sulphur Sulphur molecule consists of 8 atoms in a ring form

Ammonium (NH4+) salts

• Ammonium nitrate – NH4NO3

• Ammonium sulphate – (NH4)2SO4

• Ammonium chloride – NH4Cl