Uses of chlorine and chlorate

Question 1

What type of reaction forms bleach?

Answer 1

A disproportionation reaction.

Question 2

How to form bleach?

Answer 2

Mixing chlorine and cold, dilute sodium hydroxide will form sodium chlorate(I) otherwise known as bleach.
2NaOH + Cl2 –> NaClO + NaCl + H20

Question 3

What can you use sodium chlorate(I) (bleach) for?

Answer 3

Cleaning agent, treating water, bleaching fabrics and paper

Question 4

The reaction of chlorine with water:

Answer 4

H2O + Cl2 –> 2H+ + Cl- + ClO-

Question 5

The reaction of chlorine with water with UV light(sun) present:

Answer 5

2H2O + Cl2 –> 4H+ + 2Cl- + O2

Question 6

Why is the reaction of chlorine with water with UV light(sun) a problem?

Answer 6

No chlorate ions are produced (ClO-) which is the molecule that actually kills the bacteria. Therefore in pools outside chlorine must be replaced regularly.

Question 7

What are the advantages of chlorinated 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 can discolour water and give it a bad smell
• Overall benefits outweigh negatives because it stops cholera and other waterborne disease outbreaks

Question 8

What are the disadvantages of chlorinated water?

Answer 8

• Chlorine gas is toxic and irritates the respiratory system.
• Liquid chlorine causes severe chemical burns
• Chlorine can react with organic compounds present in the water to make chloroalkanes. This has been linked to being a carcinogen.