Pages in this set

Page 1

Preview of page 1
AQA GCSE SCIENCE - C2 6 - Electrolysis

a) Electrolysis is the decomposition of a substance to give simpler substances.
The substance being electrolysed has to be an ionic compound.
b) The substance being decomposed is called the electrolyte.
c) In electrolysis the electric current enters and leaves the…

Page 2

Preview of page 2
AQA GCSE SCIENCE - C2 6 - Electrolysis

Here is what happens during electrolysis:

Positively charged ions move to the negative electrode during electrolysis.
They receive electrons and are reduced.
Negatively charged ions move to the positive electrode during electrolysis.
They lose electrons and are oxidised.

Predicting the products of…

Page 3

Preview of page 3
AQA GCSE SCIENCE - C2 6 - Electrolysis

The reactivity series of metal - carbon and hydrogen are not metals, but they are
shown for comparison
So the electrolysis of copper chloride solution produces copper at the negative
electrode. But the electrolysis of sodium chloride solution produces hydrogen.

At the…

Page 4

Preview of page 4
AQA GCSE SCIENCE - C2 6 - Electrolysis

copper chloride, CuCl2 copper chlorine

copper sulfate, CuSO4 copper oxygen

sodium chloride, NaCl hydrogen chlorine

hydrochloric acid, HCl hydrogen chlorine

sulfuric acid, H2SO4 hydrogen oxygen

Purification of copper
Copper is a good conductor of electricity, and is used extensively to make electrical…

Page 5

Preview of page 5
AQA GCSE SCIENCE - C2 6 - Electrolysis

Electrolysis of sodium chloride solution
These three products - hydrogen, chlorine and sodium hydroxide - have important
uses in the chemical industry:

making ammonia
making margarine

killing bacteria in drinking water
killing bacteria in swimming pools
making bleach
making disinfectants…

Page 6

Preview of page 6
AQA GCSE SCIENCE - C2 6 - Electrolysis

At the negative electrode
Positive ions gain electrons at the negative electrode, so are reduced.
In aluminium extraction: Al3+ + 3e- Al
In copper purification: Cu2+ + 2e- Cu
Electrolysis of sodium chloride solution: 2H+ + 2e- H2

At the positive electrode…


No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »