Equal amounts of marble chips are reacted separately with 100cm3 of hydrochloric acid of different concentrations. If all the marble chips reacted; which of the following remained the same in each case?

A.

Average rate of evoluton of gas

B.

Total mass of gas evolved during the reaction

C.

Time taken for the reaction to reach completion

D.

Initial reaction rates

Correct answer is B

The total mass of gas evolved during the reaction will remain the same in each case. This is because the amount of marble chips is the same in each case, and the reaction goes to completion. Therefore, the same amount of gas will be produced in each case, regardless of the concentration of the hydrochloric acid.