Question

To prepare one gram of hydrogen molecules using hydrochloric acid, how many grams of zinc should be taken?

Answer 1

$Zn+2HCl\to ZnC{l}_2+H_2\uparrow$

The gram atomic mass of zinc is $=65$ g and Gram molecular mass of Hydrogen $=2$ g From the above equation we can understand that $65$ g of zinc gives $2$ g of hydrogen molecules. To prepare $1$ g of hydrogen molecules we need $32.5$ g of zinc.