Topic 3 - Electrolysis

Question 1

What is electrolysis?

Answer 1

The breakdown of an electrolyte using electricity

Question 2

What is an electrolyte?

Answer 2

The liquid that is used in electrolysis

Question 3

What is an anode?

Answer 3

The positive electrode

Question 4

What is a cathode?

Answer 4

The negative electrode

Question 5

What is an anion?

Answer 5

A negative ion that is attracted to the anode

Question 6

What is a cation?

Answer 6

A positive ion that is attracted to the cathode

Question 7

What does “PANIC” mean?

Answer 7

Positive
Anode,
Negative
Is
Cathode

Question 8

Have cations lost or gained electrons?

Answer 8

Cations have lost electrons (positively charged)

Question 9

Have anions lost or gained electrons?

Answer 9

Anions have gained electrons (negatively charged)

Question 10

Why can ionic compounds conduct electricity when molten?

Answer 10

When solid, ionic compounds cannot conduct electricity, as the ions are fixed in place and cannot move. When molten, though, the ions aare free to move and carry an electric current.

Question 11

What does OIL RIG stand for?

Answer 11

Oxidation Is Loss (of electrons)

Reduction Is Gain (of electrons)

Question 12

What does electrolysis do to an electrolyte?

Answer 12

Electrolysis splits an electrolyte back up into its elements, i.e. changing back from ions to atoms

Question 13

At the cathode, do substances gain or lose electrons?

Answer 13

At the cathode, species always GAIN electrons

Reduction

Question 14

At the anode, do substances gain or lose electrons?

Answer 14

At the anode, species always LOSE electrons

Oxidation

Question 15

What 2Cl- -> Cl2 + 2e- an example of?

Answer 15

A half equation

Question 16

How does electroplating work?

Answer 16

Having the object you want to cover as the cathode, and what you cover it with as the anode, by electrolysing (with a solution of the substance at the anode as the electrolyte), you can electroplate the object

Question 17

How is copper purified using electrolysis?

Answer 17

There is two strips of copper, a pure one and an impure one. Copper molecules move from the impure strip to the pure one. The impurities do not move and fall to the bottom.