SC2e Drinking Water

Question 1

What is desalination

Answer 1

The process of producing pure water from sea water , it can be achieved using simple distillation

Question 2

How is sea water separated from dissolved salts using simple distillation

Answer 2

Sea water is heated so that water vapour leaves it quickly. This vapour is then cooled and condensed forming water without the dissolved slats

Question 3

What is a disadvantage of distillation used to purify water

Answer 3

It is not usually a suitable method for producing large quantities of water .

Question 4

About chemical analysis

Answer 4

Involves the use of chemical reactions or sensitive machines to identify and measure the substances in a sample

Question 5

One key step to make sure chemical analysis is correct

Answer 5

The water needs to be free of any dissolved salts to prevent the outcome of an inaccurate test result .

Question 6

What can the fresh water from lakes and rivers contain

Answer 6

Objects such as leaves and twigs
Small insoluble particles such as grit
Soluble substances including salts pesticides and fertilisers
Bacteria and other microorganisms that may be harmful to health

Question 7

The steps that need to be taken to make dirty water drinkable

Answer 7

Screening , using a sieve

Sedimentation , particles are allowed to settle out

Filtration

Chlorination , chlorine is added to kill microorganisms in the treated water