What does a half equation represent?
The reaction at one electrode, showing the particles involved and the electrons transferred.
AQA GCSE Combined Science: Trilogy (8464) — Chemistry — Higher · 5.4.3.5
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What does a half equation represent?
The reaction at one electrode, showing the particles involved and the electrons transferred.
Where do electrons appear in a reduction half equation, and why?
On the left, because the ion gains electrons.
Where do electrons normally appear in an oxidation half equation, and why?
On the right, because the ion loses electrons.
What two things must balance in a half equation?
The atoms and the overall charge.
How else can electron loss be represented in an oxidation half equation?
By subtracting electrons from the left-hand side.
In electrolysis, what are the charges of the cathode and anode?
The cathode is negative; the anode is positive.
Which ions are attracted to the cathode during electrolysis?
Positively charged ions.
Which ions are attracted to the anode during electrolysis?
Negatively charged ions.
What electron transfer occurs at the cathode during electrolysis, and what type of redox reaction is it?
Ions gain electrons: this is reduction.
What electron transfer occurs at the anode during electrolysis, and what type of redox reaction is it?
Ions lose electrons: this is oxidation.