Water Sterilisation

Question 1

Adding chlorine to water…

Answer 1

Can kill bacteria

Question 2

Adding water to chlorine will produce..

Answer 2

Chlorate(1) ions

ClO

Question 3

Equation in water sterilisation

Answer 3

H2O + Cl2 -> 2H+ + Cl- + ClO-

Question 4

In water sterilisation chlorine has been

Answer 4

Simultaneously oxidised and reduced (disproportionation)

Question 5

Sunlight can

Answer 5

Decompose chlorinated water

No ClO- is made

Question 6

Equation for sunlight decomposing chlorinated water

Answer 6

2H2O + Cl2 -> 4H+ + 2Cl- + O2

Question 7

Advantages of drinking chlorinated drinking water

Answer 7

Destroys microorganisms that cause disease

Long lasting so reduces bacteria build up further down the supply.

Reduces the growth of algae that discolours water and can give it a bad smell and taste

Question 8

Disadvantages of drinking chlorinated water

Answer 8

Chlorine gas is toxic and irritates the respiratory system

Liquid chlorine causes severe chemical burns to the skin.

Question 9

Big disadvantage of chlorinated drinking water

Answer 9

Chlorine can react with organic compounds present in the water to make chloroalkanes.

These have been linked with causing cancer.

Question 10

However the risk of not chlorinating water.

Answer 10

However the risk of not chlorinating water

could lead to a cholera epidemic.