ELECTROLYSIS OF BRINE

Question 1

What is brine?

Answer 1

Sodium chloride solution

Question 2

Why do we put brine through electrolysis?

Answer 2

To extract chlorine, sodium hydroxide and hydrogen.

Question 3

What do you sodium hydroxide used for?

Answer 3

Cleaning agents

Manufacture of paper

Question 4

What do we use chlorine for?

Answer 4

Sanitation of pools

Making plastics

Question 5

What do we use hydrogen for?

Answer 5

Part of fertiliser
Paint industry
Making HCl

Question 6

In the electrolysis of brine, what is formed at the anode?

Answer 6

Chlorine

Question 7

In the electrolysis of brine, what is formed at the cathode?

Answer 7

Hydrogen

Question 8

How do we get sodium hydroxide from the electrolysis of brine?

Answer 8

The solution left behind is sodium hydroxide solution

Question 9

What is the cathode made of the electrolysis of brine?

Answer 9

A metal. The metal often is mercury.

Question 10

Why is it important to recognise that mercury is part of the electrolysis of brine?

Answer 10

Because mercury is toxic and some of it will be released into the environment. This is clearly not good.

Question 11

What are two environmental impacts of the electrolysis of brine?

Answer 11

Mercury is toxic and some is released into the environment as a result of electrolysis.

It requires a lot of electricity. Electricity is made through the burning of fossil fuels.

Question 12

What is the half equation that occurs at the anode?

Answer 12

2Cl- –> Cl2 + 2e-

Question 13

What is the half equation that occurs at the cathode?

Answer 13

2H+ + 2e- –> H2

Question 14

Why does hydrogen collect at the cathode rather than sodium?

Answer 14

Because sodium is more reactive than hydrogen