What volume of hydrogen at STP is produced when 2.5 g of zinc react with an excess of hydrochloric acid in the reaction Zn + 2HCl -> ZnCl_2 + H_2?

1 Answer
Feb 28, 2016

0.86 "L"

Explanation:

1 "mol" of "Zn" has mass of 65.39 "g".

The amount of "Zn" is frac{2.5 "g"}{65.39 "g/mol"} = 0.038 "mol".

The amount of "H"_2 produced is the same as the amount of "Zn" consumed (0.038 "mol").

1 "mol" of ideal gas will occupy 22.4 "L" at STP.

The "H"_2 will occupy 0.038 "mol" xx 22.4 "L/mol" = 0.86 "L".