C2.5 Salts and Electrolysis

Question 1

Acids ionise in water to produce….

Answer 1

hydrogen ions H+

Question 2

Alkalis ionise in water to produce….

Answer 2

Hydroxide ions, OH-

Question 3

What is a base?

Answer 3

A substance that neutralises an acid

Question 4

Suggest the pH of hydrochloric acid

Answer 4

1-4

Question 5

Suggest the pH of sodium hydroxide

Answer 5

10-14

Question 6

Acid + Metal =

Answer 6

Salt + Hydrogen

MASH

Question 7

Acid + Metal Oxide =

Answer 7

Salt + Water

Question 8

Acid + Alkali =

Answer 8

Salt + Water

Question 9

Acid + Metal Carbonate =

Answer 9

Salt + carbon dioxide + water

Question 10

Magnesium + Hydrochloric acid =

Answer 10

Magnesium Chloride + Hydrogen

Question 11

Sodium Hydroxide + Nitric acid =

Answer 11

Sodium nitrate + water

Question 12

Copper Oxide + sulphuric acid =

Answer 12

Copper sulphate + water

Question 13

Calcium Carbonate + Hydrochloric acid =

Answer 13

Calcium chloride + Carbon Dioxide + water

Question 14

List the steps to make copper sulphate crystals

Answer 14

Warm sulphuric acid
Add copper oxide until it is in excess
Filter the excess copper oxide
Evaporate the water

Question 15

Lead nitrate + Potassium Iodide =

Answer 15

Lead iodide + Potassium nitrate

Question 16

How can a precipitate, such as lead iodide, be removed from a solution?

Answer 16

Filter it

Question 17

What is the positive electrode in electrolysis called?

Answer 17

Anode

PANic

Question 18

What is the negative electrode in electrolysis called?

Answer 18

Cathode

PANiC

Question 19

In the electrolysis of lead iodide, why does the lead iodide have to be melted?

Answer 19

so the ions can move

and carry the charge

Question 20

In the electrolysis of lead iodide, which electrode do the lead ions go to?

Answer 20

Cathode

Question 21

Explain why copper ions go to the cathode

Answer 21

The cathode is negative
Copper ions are positive
Opposite charges attract

Question 22

Explain why chloride ions go to the anode

Answer 22

The anode is positive
Chloride ions are negative
Opposite charges attract

Question 23

Finish the following equation

Pb2+ + __ e- –> Pb

Answer 23

Pb2+ + 2e- –> Pb

Question 24

Finish the following equation

_Cl- —> Cl2 + __e-

Answer 24

2Cl- —> Cl2 + 2e-

Question 25

How does a copper ion, Cu2+, become a copper ion?

Answer 25

By gaining two electrons

Question 26

What is the aluminium ore called?

Answer 26

Bauxite

Question 27

Why is molten cryolite added to the bauxite?

Answer 27

To reduce the melting point | so less energy is required

Question 28

Name the three products of the electrolysis of brine

Answer 28

Sodium hydroxide Hydrogen Chlorine (CatHy's AnCls)

Question 29

The loss of electrons is called

Answer 29

Oxidation | OILRIG

Question 30

The gain of electrons is called

Answer 30

Reduction | OILRIG

Question 31

Why is hydrogen produced instead of sodium in the electrolysis of brine?

Answer 31

Sodium is more reactive than hydrogen

Question 32

Why is electroplating used?

Answer 32

To make objects look better To protect the metal from corroding It's cheaper than using the pure metal