A student adds excess zinc carbonate to dilute sulfuric acid and filters the mixture. What is the purpose of using excess zinc carbonate in this preparation?

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Question

A student adds excess zinc carbonate to dilute sulfuric acid and filters the mixture. What is the purpose of using excess zinc carbonate in this preparation?

Accepted Answer

To ensure all the acid is completely used up — Excess carbonate ensures all the sulfuric acid is neutralised so that no acid remains in the filtrate, giving a pure salt solution. Option A is incorrect because excess reagent does not significantly affect rate once concentration is limiting. Option C is incorrect as excess solid is removed by filtration. Option D has no chemical basis.

Answer

To prevent the salt from crystallising too quickly

Answer

To increase the rate of the reaction with the acid

Answer

To ensure all the acid is completely used up

Answer

To increase the concentration of the salt formed

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