Hydrogen gas is prepared in the laboratory by reacting dilute HCl with granulated zinc. Following reaction takes place. Zn + 2HCl → ZnCl 2 + H 2 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 = 65.3 u.

Question

Philoid · Accepted Answer

The atomic mass of Zn is given to be 65.3. Hence 1 mole of Zn has 65.3g. 1 mole of hydrogen gas occupies 22.7L at STP.

The equation can be written as

Since 63.5g Zn gives 22.7L of H₂ gas, 32.65g of Zn will give 32.65 x 22.7/63.5 = 11.35L of H₂ gas.