JEE MainChemistrySome Basic Concepts of Chemistry
A 0.54 g sample of aluminium reacts completely with an excess of dilute hydrochloric acid. The volume of hydrogen gas evolved at STP is: (Given: Molar mass of Al = 27 g mol ⁻¹ , Molar volume of a gas at STP = 22.4 L mol ⁻¹ )
Options
- A672 mL
- B448 mL
- C1344 mL
- D0.672 mL
Correct answer
A. 672 mL
Step-by-step solution
The balanced chemical equation for the reaction is: 2 Al + 6 HCl 2 AlCl ₃ + 3 H ₂ Moles of Al reacted = 0.54 27 = 0.02 mol From the stoichiometry of the reaction, 2 moles of Al produce 3 moles of H ₂ . Moles of H ₂ produced = 3 2 0.02 = 0.03 mol Volume of H ₂ at STP = 0.03 mol 22.4 L mol ⁻¹ = 0.672 L Converting to mL: Volume = 0.672 1000 = 672 mL Answer: 672 mL