GCSE Chemistry, 4.10- Using resource.

What is meant by ‘potable water’. [1 mark]

Water that safe to drink

In the UK, there are a lot of rivers.

Explain how could we obtain potable water from rivers. [4 marks]

• Sedimentation- remove large materials.

• Filtration- remove all solid material through filter bed.

• Sterilisation- using chlorine to kill all microorganism.

A country has no lake and rainfall.

Suggest two possible method to obtain potable water.

• Reverse osmosis.

• Distillation.

Describe how waste water treated. [4 marks]

• Screening- remove large materials.

• Sedimentation- produce sludge and effluent.

• Anaerobic bacteria digest the sludge.

• Aerobic bacterial digest effluent.

Describe and explain the process of phytomining for extracting magnesium. [4 marks]

• Plants grow on lands that have magnesium compound.

• So, plant absorb magnesium compound.

• Plant is burned and contain ash.

• Electrolysis.

Describe and explain the process of bioleching for extracting magnesium. [4 marks]

• Bacteria mix with low grade ore.

• Leachate produced.

• Electrolysis.

Describe 4 main stage of life cycle assessment.

4 marks]

• Extracting and processing raw material.

• Manufacturing and package.

• Use and operation during its lifetime.

• Disposal at the end of its useful life, include transport and distribution at each stage.

Suggest 2 problems life cycle assessment.

[2 marks]

• Cannot be certain how damaging to the environment.

• Biased

Describe how could we recycle glass product.

[1 mark]

Melted to make different product.

What is meant by ‘corrosion’. [2 marks]

Destruction of materials by chemical reaction with substance in the environment.

Figure show nail in a different test tubes.

Describe the condition that require corrosion of metal.

Give your reason to your answer. [2 marks]

• Nail has change colour.

• This show air and water are required to let metal corroded.

Describe how sacrificial protection can prevent corrosion. [1 mark]

More reactive metal corroded first, even it get scratched.

State the metal inside of bronze and use of bronze.

[2 marks]

• Copper and tin.

• Statues.

State the metal inside of brass and use of brass.

[2 marks]

• Copper and zinc.

• Door handles.

State the use of high carbon steel. [1 mark]

Cutting tools.

State the use of low carbon steel. [1 mark]

Make car bodies.

Describe how soda-lime glass is made. [1 mark]

Heating mixture of sand, sodium carbonate and limestone.

Describe how borosilicate glass is made. [1 mark]

Melting a mixture of sand and boron trioxide.

Describe how most composites are made.

[2 marks]

Reinforcement (fibres and fragments) surrounded by matrix and binder

Give two example of composites. [2 marks]

Carbon fibre and concrete.

State all factors that determine the properties of polymer. [3 marks]

Temperature, pressure and catalyst.

Explain why thermosoftening polymers easy to melt. [2 marks]

• Weak intermolecular forces between polymer strands.

• Require less energy to break it.

Explain why thermosetting polymers is not easy to melt. [2 marks]

• Strong cross link.

• Require a lot of energy to break it.

What are the best condition for high yield of ammonia in haber process

450 ^oC, 200 atm and iron catalyst.

Describe how do we make single superphosphate.

[1 mark]

Treat phosphate rock with sulfuric acid.

Describe how do we make triple superphosphate.

[1 mark]

Treat phosphate rock with phosphoric acid.