C3.4.2 - Electrolysis Of Solutions

Question 1

What are inert electrodes?

Answer 1

Electrodes which do not change in electrolysis

Question 2

What are inert electrodes usually made from?

Answer 2

Unreactive metals

Question 3

What are inert electrodes used for?

Answer 3

The electrolysis of many ionic compounds in the liquid or aqueous state

Question 4

Describe what happens in the electrolysis of water.

Answer 4

Hydrogen ions in water are discharged at the cathode as hydrogen gas, and hydroxide ions are discharged at the anode which forms water and oxygen

Question 5

Why do ions have to compete to be discharged in the electrolysis of an aqueous solution?

Answer 5

Because only one ion can be discharged at each electrode and there are ions from the dissolved ionic compound and the hydrogen and hydroxide ions of water

Question 6

What is produced at the cathode in the electrolysis of an aqueous solution?

Answer 6

Hydrogen unless there are ions from a less reactive metal present, in which case that metal is produced

Question 7

What is produced at the anode of an electrolysis of an aqueous solution?

Answer 7

Oxygen unless ions from a Group 7 element at a high concentration is present, in which case that element is produced

Question 8

How can you determine whether something is less reactive than something else?

Answer 8

Using a reactivity series