Electrolysis Flashcards

1
Q

What are electrolytes?

A

Ionic compounds that are:

  • in the molten state (heated so they become liquids), or
  • dissolved in water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is electrolysis?

A

A process where electrical energy (from a direct current supply) breaks down electrolytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which kind of electrical supply is always used for electrolysis?

A

Direct current (DC)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the name of the positively-charged electrode?

A

Anode

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the name of the negatively-charged electrode?

A

Cathode

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the name of the positively-charged ion?

A

Cation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the name of the negatively-charged ion?

A

Anion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Which electrode do cations move to?

A

The cathode

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which electrode do anions move to?

A

The anode

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What happens to positive ions at the cathode?

A

They gain electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What happens to negative ions at the anode?

A

They lose electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What happens at the cathode in the electrolysis of lead bromide?

A

Pb2+ ions gain electrons at the cathode and become Pb atoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What happens at the anode in the electrolysis of lead bromide?

A

Br- ions lose electrons at the anode and become Br atoms, which pair up to form Br2 molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What forms at the cathode in the electrolysis of calcium chloride?

A

Calcium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What forms at the anode in the electrolysis of calcium chloride?

A

Chlorine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What happens at the cathode in the electrolysis of acidified water?

A

H+ ions are attracted to the cathode, gain electrons and form hydrogen gas

17
Q

What happens at the anode in the electrolysis of acidified water?

A

OH- ions are attracted to the anode, lose electrons and form oxygen gas

18
Q

In the electrolysis of a dissolved ionic compound, when is hydrogen produced at the cathode?

A

If the metal is more reactive than hydrogen

19
Q

Which three metals are less reactive than hydrogen?

A
  • Copper
  • Silver
  • Gold
20
Q

In the electrolysis of dissolved ionic compounds, when is oxygen NOT produced at the anode?

A

When halide ions (chloride, bromide or iodide ions) are present

21
Q

In the electrolysis of dissolved sodium chloride, what is given off at the anode?

A

Chlorine

22
Q

In the electrolysis of dissolved copper sulfate, what is given off at the anode?

A

Oxygen

23
Q

Give the half equation for the production of sodium at the cathode.

A

Na+ + e- → Na

24
Q

Give the half equation for the production of lead at the cathode.

A

Pb2+ + 2e- → Pb

25
Q

Give the half equation for the production of chlorine at the anode.

A

2Cl- → Cl2 + 2e-