electrolysis

Question 1

What type of electrodes are used in electrolysis experiments?

Answer 1

Inert electrodes, made out of either carbon or platinum, are used to ensure they don’t react with the electrolyte or the products.

Question 2

What happens at the cathode during electrolysis of sodium chloride solution?

Answer 2

At the cathode, hydrogen gas is produced from the reduction of hydrogen ions (H⁺) in water.

Question 3

How can you test for hydrogen gas?

Answer 3

Lit splint test – a ‘pop’ sound indicates the presence of hydrogen gas.

Question 4

What happens at the anode during electrolysis of sodium chloride solution?

Answer 4

At the anode, chlorine gas is produced from the oxidation of chloride ions (Cl⁻).

Question 5

How do you test for chlorine gas?

Answer 5

To test for chlorine gas, use damp blue litmus paper – it will turn red and then bleach white.

Question 6

Why do we use inert electrodes in electrolysis?

Answer 6

Inert electrodes are used because they do not react with the electrolyte or the products during electrolysis, ensuring they don’t interfere with the reactions.

Question 7

What is the role of the electrolyte in electrolysis?

Answer 7

The electrolyte transfers electrical energy, contains free-moving ions, and allows them to be discharged at the electrodes during electrolysis.

Question 8

What is electrolysis?

Answer 8

Electrolysis is the process of using electricity to break down ionic compounds into their elements by discharging the ions at the electrodes.