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Question Marble chips (calcium carbonate) react with hydrochloric acid in an exothermic
reaction.
calcium carbonate + hydrochloric acid – calcium chloride + water + carbon dioxide
When excess marble chips are added to dilute hydrochloric acid the rate of the reaction starts
off fast, then gets slower until the reaction stops.
Why does the reaction rate get slower?

a. The concentration of the hydrochloric acid is decreasing.

b. The concentration of calcium chloride is increasing.

c. The calcium carbonate is completely used up.

d. The temperature of the mixture decreases.