Hydrogen gas is prepared in the laboratory by reacting dilute HCl with granulated zinc. Following reaction takes place

Zn + 2HCl ZnCl2 + H2

Calculate the volume of hydrogen gas liberated at STP when 32.65 g of zinc reacts with HCl. 1 mol of a gas occupies 22.7 L volume at STP; atomic mass of Zn=65.3u

Given that, mass of Zn=32.65 g
1 mole of gas occupies=22.7 L volume at STP
Atomic mass of Zn=65.3u
The given equation is
Zn65.3 g+2HClZnCl2+H21 mol=22.7 L at STP
From the above equation, it is clear that
65.3 g Zn, when reacts with HCl, produces=22.7 L of H2 at STP
 32.65 g Zn, when reacts with HCl, will produce=22.7×32.6565.3=11.35 L of H2 at STP