Preventing rusting by using sacrificial protection

1 mark · Easy

State why a sacrificial anode used to protect iron must be more reactive than iron.

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So that the anode (the more reactive metal) can be oxidised instead of iron.

Also accept: It will corrode instead of iron.; So that the more reactive metal is oxidised and protects the iron.

Common mistakes: Because it lasts longer; Because it is cheaper

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Marking points

B1 · 1 mark · States that the more reactive metal is oxidised/corrodes instead of iron.

Worked solution

Because a more reactive metal will be oxidised and corrode instead of the iron, providing protection.