What are catalysts?

2 marks · Easy

If 0.20 g of manganese(IV) oxide is used to catalyse four separate 100 cm³ portions of hydrogen peroxide, how much manganese(IV) oxide will remain after all four reactions are completed?

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0.20 g (±0.01)

Also accept: 0.20 grams; still 0.20 g; mass unchanged

Common mistakes: Multiplying 0.20 g by 4

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Marking points

M1 · 1 mark · Recognises that mass of manganese(IV) oxide does not decrease.

A1 · 1 mark · Gives final answer: 0.20 g.

Worked solution

Manganese(IV) oxide is a catalyst, so it is not used up in the reaction.

After four reactions, 0.20 g remains.