2.4 g of magnesium metal is added to 100 mL of a 1.0 M HCl solution. The volume of hydrogen gas produced at STP is: (Given: Molar mass of Mg = 24 g mol ⁻¹ , Molar volume of gas at STP = 22.4 L mol ⁻¹ )

Step-by-step solution

The balanced chemical equation for the reaction is: Mg (s) + 2 HCl (aq) MgCl ₂(aq) + H ₂(g) Moles of Mg initially present = 2.4 g 24 g mol ⁻¹ = 0.1 mol Moles of HCl initially present = 100 mL 1 L 1000 mL 1.0 mol L ⁻¹ = 0.1 mol From the stoichiometry of the reaction, 1 mole of Mg requires 2 moles of HCl . Thus, 0.1 mol of Mg would require 0.2 mol of HCl . Since only 0.1 mol of HCl is available, HCl is the limiting reagent. Moles of H ₂ produced = 1 2 Moles of HCl consumed = 1 2 0.1 mol = 0.05 mol Volume of H ₂ gas a