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 = 65.3 u.
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.
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