Electrolysis PAPER 1

Question 1

What is electrolysis?

Answer 1

The breakdown of substance using electricity

Question 2

What is an anode?

Answer 2

Positive electrode

Question 3

What is a cathode?

Answer 3

Negative electrode

Question 4

What is an electrolyte?

Answer 4

A molten or dissolved ionic compound where ions can move freely

Question 5

Where do negative ions go to?

Answer 5

Anode

Question 6

Where do positive ions go to?

Answer 6

Cathode

Question 7

What does inert mean?

Answer 7

Unreactive

Question 8

Why must the electrodes be inert?

Answer 8

So they dont react with the electrolyte

Question 9

Why do the ions move to the electrodes?

Answer 9

Because a current is passed through the electrolyte pulling the ions to the electrodes

Question 10

What is produced at the cathode?

Answer 10

A pure element

Question 11

Electrons are _____ at the cathode

Answer 11

Gained

Question 12

Electrons are _____ at the anode

Answer 12

Lost

Question 13

What is produced at the anode?

Answer 13

A pure element

Question 14

Where are non-metals produced?

Answer 14

At the anode

Question 15

Where are metals produced?

Answer 15

At the cathode

Question 16

Why is hydrogen gas produced at the cathode with an aqueous solution of sodium?

Answer 16

Hydrogen is less reactive than sodium so will form at the cathode

Question 17

Why is electrolysis only used with metals more reactive than carbon?

Answer 17

• metals more reactive than carbon cannot be extracted using carbon displacement
• so electrolysis must be used

Question 18

Method: electrolysis?

Answer 18

1) add 50cm³ of CuCl solution to beaker using measuring cylinder
2) attach crocodile leads to the rods. Connect the rods to the D.C terminals of low voltage
3) add electrodes to the solution. The rods must not touch each other
4) set 4v on the power supply and switch it on
5) observe electrodes and use tweezers to hold litmus paper next to positive electrode
6) should observe bubbles and litmus paper blue to white. Copper should form at cathode
7) repeat with different solution