Electrolysis

Question 1

Ionic compounds contains…

Answer 1

Charged atoms called ions.

Question 2

Ionic solids

Answer 2

Ions are locked and cannot move, so it does not conduct electricity.

Question 3

When ionic compound dissolved or molten

Answer 3

Ions are free to move so it can carry the charge.

Question 4

Electrolysis

Answer 4

Passing an electric current through a molten or dissolved ionic compound. It breaks down to its elements.
E.g. lead bromide = lead + bromide

Question 5

Electrolyte

Answer 5

Is molten or dissolved ionic compound that we pass the electric current through.

Question 6

Ions in electrolysis

Answer 6

Positive ions are attracted to negative electrode. Negative ions are attracted to positive electrode.

Question 7

Electrode

Answer 7

Is made of materials which conduct electricity such as graphite.

Question 8

Electroplating

Answer 8

Objects can be plated in metal, if we make them into the negative electrode.

Question 9

Positive metal ions move to….

Answer 9

negative electrode and stick there crating layer of metal.

Question 10

Uses of Electroplating

Answer 10

• protect metals from corrosion
• make the object look more attractive
• to increase the hardness of a surface area
• to save money, creating a thin layer of an expensive metal

Question 11

Positive electrode

Answer 11

Anode

Question 12

Negative electrode

Answer 12

Cathode

Question 13

Positive Ions

Answer 13

Cathodes

Question 14

Negative Ions

Answer 14

Anodes

Question 15

Ionic substances have…

Answer 15

a very high melting point, so it takes a lot of energy to melt them. However, some can be dissolved in water, creating free ions also.

Question 16

Only metals of low reactivity, below…

Answer 16

hydrogen in the reactivity series are deposited from the aqueous solution. E.g. copper Otherwise, hydrogen gas is produced.

Question 17

Covalent compounds cannot usually…

Answer 17

be electrolysed unless they react in water to form ions.

Question 18

Water forms…

Answer 18

hydrogen ions and hydroxide ions

Question 19

It is important that electrode does not…

Answer 19

react with the solution. Platinum is often used as it is very unreactive metal.

Question 20

Inert

Answer 20

Means it is not reactive.

Question 21

Ionise

Answer 21

Means split.

Question 22

What is produced at anode?

Answer 22

If the aqueous solution contains halide ions then the halogen(gas) will be produced at the anode.

Question 23

The half-equation of halogens

Answer 23

2H- + 2e- = H2

2Cl- = Cl2 + 2e-

Question 24

Active electrodes

Answer 24

Take part in the electrolysis.