C3.3 Electrolytic Processes

Question 1

What are the names of the two electrodes?

Answer 1

The positive electrode is the anode and the negative one is the cathode.

Question 2

What are the names of charged particles?

Answer 2

Positive is Cation

Negative is Anion

Question 3

What is an electrolyte?

Answer 3

An ionic substance that is molten or dissolved in water.

Question 4

What conducts the electricity in an electrolyte?

Answer 4

The free ions.

Question 5

What is oxidation and reduction?

Answer 5

Oxidation is a loss of electrons

Reduction is a gain of electrons.

Question 6

What are half equations?

Answer 6

Equations that show what happens to ions at the cathode or anode.

Question 7

What are the products for electrolysis of Sodium chloride?

Answer 7

Sodium and chlorine.

Question 8

Which ion is discharged at the anode for electrolysis of a dissolved electrolyte?

Answer 8

The simplest one.

Question 9

What is discharged at the cathode?

Answer 9

Either a metal that is less reactive than hydrogen or hydrogen.

Question 10

What are the products of the electrolysis of copper chloride?

Answer 10

Cathode: copper
Anode: Chlorine

Question 11

What are the products of the electrolysis of Copper sulphate?

Answer 11

Cathode: copper
Anode: oxygen

Question 12

What are the products of the electrolysis of Sodium sulphate?

Answer 12

Cathode: hydrogen
Anode: oxygen

Question 13

In order to purify copper, which electrode is pure and which is impure?

Answer 13

The anode is impure and the cathode pure.

Question 14

During copper purification by electrolysis, what happens at the anode?

Answer 14

Copper particles dissolve into the solution. The anode decreases in mass.

Question 15

During copper purification by electrolysis, what happens at the cathode?

Answer 15

The copper ions in the solution are discharged at the cathode. It increases in mass.

Question 16

What mass changes occur during the electrolysis of copper sulphate using copper electrodes?

Answer 16

The cathode gains mass whilst the anode loses mass.

Question 17

What is electroplating?

Answer 17

Applying a thin layer of metal to another metal.

Question 18

What are the purposes of electroplating with gold or silver?

Answer 18

To make it look nicer
To add value
To make it unreactive.

Question 19

What is the purpose of electroplating with non valuable metals?

Answer 19

To protect the metal from corrosion
To make the metal weather resistant
To make it unreactive.

Question 20

What is the cathode, anode and electrolyte during electroplating?

Answer 20

The cathode will be the object that needs to be electroplated
The anode is a bar of the metal used for electroplating.
The electrolyte contains atoms of the metal you want to electroplate with.

Question 21

What household item is electroplated?

Answer 21

Iron cutlery is electroplated with nickel or chromium.

Question 22

In terms of electrons, what happens at the electrodes?

Answer 22

At the cathode, electrons are transferred to the positive ions
At the anode, electrons negative ions lose electrons