In the reaction, Zn + HCl-> ZnCl2 + H2, 25 grams Zn are reacted with 17.5 grams HCl. How many grams of H2 will be produced?

A. 0.382 g of H2

B. 0.479 g of H2

C. 0.7865 g of H2

D. 0.484 g of H2

The full equation should be:

Zn + 2 HCl-> ZnCl2 + H2

The number of Zn atoms in reactant would be: 25g / (65.38g/mol) = 0.3824 mol

The number of HCl molecules in reactant would be: 17.5g / (36.46g/mol) = 0.479mol

Since you use 2 HCl for each Zn, HCl would be depleted first. For every 2 HCl molecule, there will be 1 H2 formed.

The mass of H2 molecule formed would be: 0.479mol * 1/2 * 2g/mol = 0.479g