10.1 - Uses and Reactions of chlorines

Question 1

What is a disproportionation reaction

Answer 1

a reaction in which the same species is oxidised and reduced as well

Question 2

What is an example of a disproportionation reaction?

Answer 2

reaction of chlorine with dilute alkali
* however different reactions take place at different temperatures

Question 3

Chlorine reacting in cold alkali (15oC)

show the reducing and oxidating reaction
what does this therefore show?

Answer 3

Question 4

What can chlorine be used for?

Answer 4

can be used to clean water and make it drinkable

Question 5

what type of reaction is chlorine in water?

Answer 5

a disproportionation reaction in which the chlorine gets both oxidised and reduced

Question 6

what does chloric(I) acid do?

Answer 6

sterilises water by killing bacteria
can further dissociate in water to form ClO-

Question 7

Reaction of chloric (I) acid dissociating

Answer 7

HClO (aq) → H+(aq) + ClO-(aq)

Question 8

what do chlorate ions act as?

Answer 8

a sterilising agent to clean the water
* used in water treatment to kill bacteria
* used to treat drinking water and the water in swimming pools

Question 9

What is the benefits to risks of water treatment to chlorine? What happens to chlorine in shallow water?

Answer 9

• the benefits to the health of water by killing bacteria outweighs its risks of toxic effects such as chlorinated hydrocarbons
• in shallow pools, the chlorine is rapidly lost from the water, chlorine has to be topped up on a regular basis due to exposure to sunlight

Question 10

Sunlight reaction to chlorine in swimming pools

Answer 10

2Cl2(g) + 2H2O (l) → 4HCl (aq) + O2(g)