Answer to Question #328603 in General Chemistry for Sucy

Question

Calculate the volume of hydrogen gas produced at STP when 30g of Zn is added to dilute hydrochloric acid at 33⁰c and 775mmHg pressure (H=1 , Zn=65 , cl =35.5) molar mass of gas at STP= 22.4 dm³

Answer 1

Zn + 2HCl = ZnCl₂ + H₂↑

n(Zn) = 30 g / 65g/mol = 0.4615 mol

1 mol Zn - 1 mol H₂

0.4615 mol Zn - x mol H₂

n(H₂) = x = 0.4615 mol.

V(H₂) = n(H₂) × V_m = 0.4615 mol × 22.4 L/mol = 10.34 L