Explanation:
Volume of gas produced = 3.36 L
as molar volume of gas at STP is 22.4 L
so
no of moles of H2 = 3.36 ÷ 22.4 = 0.15 mole
from balanced reaction equation
Zn + 2HCl = ZnCl2 + H2
Ratio of no of moles between H2 : HCl is 1:2
as H2 moles = 0.15 mole
so
HCl moles reacted = 0.15 × 2 = 0.3 mole
as HCl molar mass = 1 + 35.5 = 36.5 g/mole
so Mass of 0.3 mole of HCl = 0.3 × 36.5 = 10.85 gram
fraction of HCl in Solution
= 10.85 ÷ 109.5 = 0.1
0.1 ×100 so HCl is 10% of solution mass
