Answer to Question #179882 in Chemistry for Isabella Dinkins

Question

When aluminum reacts with hydrochloric acid, HCl, both aluminum chloride and hydrogen gas are produced. If 108 grams of aluminum is reacted, what volume of gas may be collected at STP?

Answer 1

Solution:

Balanced chemical equation:

2Al + 6HCl → 2AlCl₃ + 3H₂

According to the equation above: n(Al)/2 = n(H₂)/3

The molar mass of Al is 27 g/mol.

Hence,

Moles of Al = (108 g Al) × (1 mol Al / 27 g Al) = 4 mol Al

n(Al) = 4 mol

n(H₂) = 3 × n(Al) / 2 = (3 × 4 mol) / 2 = 6 mol

At STP, one mole of any gas occupies a volume of 22.4 L.

Thus 6 mol of H₂ occupies:

(6 mol × 22.4 L) / 1 mol = 134.4 L of H₂

Answer: 134.4 L of H₂ may be collected at STP.