Electrolysis

Question 1

what is electrolysis

Answer 1

Electrolysis involves passing an electrical current through a substance to cause oxidation and reduction at the two electrodes: The Anode (+) and Cathode (-).

Question 2

What are the conditions for Electrolysis to happen

Answer 2

Electrolysis can only happen if the ions are free to move to the electrode they’re attracted to, so for ionic compounds this can only happen when molten or in solution.

Question 3

What can Electrolysis be used for

Answer 3

Electrolysis can be used to obtain pure metals from a compound / ore e.g. aluminium from aluminium oxide

Question 4

In electrolysis if the charge of the ion is positive has to be

Answer 4

Reduction

Question 5

In electrolysis if the charge of the ion is negative it had to be

Answer 5

Oxidation

Question 6

In electrolysis ions are always attracted to the _____ electrodes

Answer 6

opposite

Question 7

What allows metals (e.g. copper) to be good conductors

Answer 7

electrons are delocalised so can flow

Question 8

what colour is (solid) copper (formed at negative electrode in electrolysis)

Answer 8

pink-brown/ brown/ pink

Question 9

why can electrolysis also be carried out on solutions

Answer 9

as the dissolved ions are free to move in the mixture

Question 10

The Cation is always attracted to the

Answer 10

cathode

Question 11

The anion is always attracted to the

Answer 11

Anode

Question 12

What is an electrolyte

Answer 12

Ionic compounds that dissolve in water to make a solution that conducts electricity

Question 13

What happens when voltage is applied across an electrolyte

Answer 13

• the charged ions are attracted to the electrode with the opposite charge.

Question 14

What is formed at the cathode

Answer 14

• Hydrogen if metal is more reactive than hydrogen
• the metal if it is less reactive than hydrogen.

Question 15

What is formed at the anode

Answer 15

• If halide ions are present, the respective halogen forms
  -If no halide, then oxygen gas forms
• ( usually a gas forms)

Question 16

Reduction takes place at the

Answer 16

cathode

Question 17

Oxidation takes place at the

Answer 17

anode

Question 18

How are pure metals obtained after being mined

Answer 18

Through electrolysis or displacement reactions

Question 19

Test for hydrogen

Answer 19

a Lit splint will produce a squeaky pop

Question 20

Test for oxygen

Answer 20

Will relight a glowing splint

Question 21

Test for chlorine(gas)

Answer 21

Bleaches blue litmus paper (Blue -> White)
(smells)

Question 22

Test for lead

Answer 22

Shiny metal forms