Topic 10

Question 1

What are composites

Answer 1

Composites are materials made up of fibres of one material wrapped in a matrix of another material e.g fibreglass

Question 2

How is glass made?

Answer 2

A mixture of limestone, sand and sodium carbonate are heated up together and after it cools it is glass

Question 3

What is corrosion

Answer 3

Corrosion is the destroying of a material because of chemical reactions with the environment

Question 4

What are the two ways of stopping corrosion

Answer 4

Barrier method:coat the material with paint or grease

Sacraficial method:have a more reactive metal with the material so that reacts first

Question 5

What is the difference between potable water and fresh water

Answer 5

Fresh water-natural water with not much dissolved in it

Potable water-water which is safe for humans to drink

Question 6

What is desalination

Answer 6

Desalination is the process of removing salt from water via reverse osmosis or distilation

Question 7

What is the haber process

Answer 7

The haber process is a process used to make ammonia from nitrogen and hydrogen

Question 8

What are the key stages of the haber process

Answer 8

1) The hydrogen and nitrogen are mixed in a 3:1 ratio
2) The mixture is passed into a reaction vessel where the temperature is 450°C and the pressure is 200atm
3) Under these conditions, ammonia gas is formed and it is then cooled into a liquid
4) The leftover hydrogen and nitrogen are recycled back to the start of the reaction chamber so none is wasted

Question 9

What is an NPK fertiliser

Answer 9

NPK fertilisers are formulations of Nitrogen Phosphorus and Potassium (K)

Question 10

What is the chemical equation for ammonium nitrate

Answer 10

ammonia+nitric acid——->ammonium nitrate