Zinc reacts with hydrochloric acid to give hydrogen and zinc chloride.
Zn+2HCl→ZnCl2+H2↑
The molar mass of Zn is 65.4 g mol−1
Molar volume od H2 at STP = 22.7 L
Number of moles of Zn =65.411.5= Number of moles of H2evolved
Volume ofH2=65.411.5×22.7L=3.99L≈4L