Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Chemistry - Unit Two > Electrolysis > Flashcards

Electrolysis Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Chemistry flashcards Periodic Table flashcards Chemistry 101 flashcards Organic Chemistry 101 flashcards
1
Q

What is electrolysis?

A

The passing of an electric current through an ionic substance that’s molten or in solution to break it down into its constituent elements.

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

What is an electrolyte?

A

The solution or molten substance containing free ions that is used in electrolysis.

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

How do you decide what electrode to use during electrolysis?

A

The electrolyte should contain the ions you are trying to obtain.

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

How does electrolysis work?

A

1) The electrodes are placed into the electrolyte
2) When the current is switched on, the annode gets a positive charge and the cathode gets a negative charge
3) The negatively charged ions in the electrolyte move towards the annode and the positively charged ions in the electrolyte are attracted to the cathode.
4) The ions either gain or lose electrons at the electrodes to make atoms which are the product of electrolysis.

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

What is oxidation?

A

The loss of electrons during a reaction.

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

What is reduction?

A

The gain of electrons in a reaction.

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

Does oxidation take place at the anode or the cathode during electrolysis?

A

Annode

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

Does reduction take place at the anode or cathode during electrolysis?

A

Cathode

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

What is a half equation?

A

An equation that shows the reactions at the electrodes.

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

How do you write a half equation?

A

1) Write the symbol for the ion on the left of the equation
2) Wrote the symbol for the neutral atom produced on the right of the equation
3) Balance the number of atoms
4) Balance the charges by adding electrons (e-)

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

How can we predict the product of electrolysis at the cathode if H+ ions are present?

A

You check if the metal ions are more or less reactive than hydrogen. The metal will stay in solution if it is MORE reactive than hydrogen.

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

How can we predict the product of electrolysis at the anode if OH- ions are present?

A

If the other ions are halides, the halide with form. Otherwise oxygen will be formed.

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

What are the three useful products of the electrolysis of sodium chloride?

A

Hydrogen, chlorine and sodium hydroxide.

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

What are two uses of Chlorine?

A

Bleach and plastics.

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

What is a use of sodium hydroxide?

A

Soap

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

What happens at the anode during the electrolysis of sodium chloride?

A

The negative chloride ions are attracted to the annode where they are oxidised to make chlorine.

17
Q

What happens at the cathode during the electrolysis of sodium chloride?

A

The positive hydrogen ions are attracted to the cathode and are reduced to form hydrogen.

18
Q

What happens to the sodium and hydroxide ions during the electrolysis of sodium chloride?

A

They are the most reactive so react first to form sodium hydroxide.

19
Q

What is the half equation at the cathode during the electrolysis of sodium chloride?

A

H+ + 2e- -> H2

20
Q

What is the half equation at the anode during the electrolysis of sodium chloride?

A

2Cl- -> Cl2 + 2e-

21
Q

What happens to aluminium oxide before electrolysis?

A

It is dissolved in molten cryolite to bring down it’s melting point to 900 degrees to save energy.

22
Q

What are the electrodes made of during the electrolysis of aluminium oxide? Why?

A

Graphite as it is a good conductor of electricity.

23
Q

What is the anode like in the electrolysis of aluminium oxide?

A

The traditional rods.

24
Q

What is the cathode like in the electrolysis of aluminium oxide?

A

The lining around the reaction

25
Q

What forms at the cathode during the electrolysis of aluminium oxide?

A

Aluminium

26
Q

What forms at the anode during the electrolysis of aluminium oxide?

A

Oxygen.

27
Q

Why do the annode need to be replaced over time during the electrolysis of aluminium oxide?

A

Because the oxygen produced reacts with the carbon in the anode to form carbon dioxide which means that the anode is eaten away at over time.

28
Q

What is the half equation at the cathode during the electrolysis of aluminium oxide?

A

Al3+ * 3e- -> Al

29
Q

What is the half equation at the anode during the electrolysis of aluminium oxide?

A

2O2- -> O2 + 4e-

30
Q

What id electroplating?

A

A process that used electrolysis to cost the surface of one metal with another.

31
Q

During electroplating what should the cathode be?

A

The metal object you want to plate.

32
Q

During electroplating what should the anode be?

A

The metal you want to use to plate the object.

33
Q

What are two used of electroplating?

A
  • Decoration

* Increasing conductivity

Chemistry - Unit Two (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions