Q11 / 75 · JEE Main 2026 (22 January Shift 1) · Chemistry
In the reaction,
$2 \mathrm{Al}(\mathrm{s})+6 \mathrm{HCl}(\mathrm{aq}) \rightarrow 2 \mathrm{Al}^{3+}(\mathrm{aq})+6 \mathrm{Cl}^{-}(\mathrm{aq})+3 \mathrm{H}_{2}(\mathrm{~g})$
$2 \mathrm{Al}(\mathrm{s})+6 \mathrm{HCl}(\mathrm{aq}) \rightarrow 2 \mathrm{Al}^{3+}(\mathrm{aq})+6 \mathrm{Cl}^{-}(\mathrm{aq})+3 \mathrm{H}_{2}(\mathrm{~g})$
- Correct answerA$11.2 \mathrm{~L} \mathrm{H}_{2}(\mathrm{~g})$ at STP is produced for every mole of HCl consumed.
- B$33.6 \mathrm{~L} \mathrm{H}_{2}(\mathrm{~g})$ is produced regardless of temperature and pressure for every mole of Al that reacts.
- C$12 \mathrm{~L} \mathrm{HCl}(\mathrm{aq})$ is consumed for every $6 \mathrm{~L} \mathrm{H}_{2}(\mathrm{~g})$ produced.
- D$67.2 \mathrm{~L} \mathrm{H}_{2}(\mathrm{~g})$ at STP is produced for every mole of Al that reacts.
Solution
Reaction: $2\text{Al}(s) + 6\text{HCl}(aq) \rightarrow 2\text{Al}^{3+}(aq) + 6\text{Cl}^-(aq) + 3\text{H}_2(g)$
Checking each option:
(1) Per 1 mole HCl: From stoichiometry, 6 mol HCl produces 3 mol H₂, so 1 mol HCl produces 0.5 mol H₂ = 11.2 L at STP. TRUE
(2) Per 1 mole Al: 2 mol Al produces 3 mol H₂, so 1 mol Al produces 1.5 mol H₂ = 33.6 L at STP only, not regardless of T and P. FALSE
(3) Volume ratio at same T,P: 6 mol HCl : 3 mol H₂ = 2:1, so 12 L HCl : 6 L H₂. TRUE
(4) Per 1 mole Al: 1.5 mol H₂ = 33.6 L, not 67.2 L. FALSE
Option (1) is correct.
Checking each option:
(1) Per 1 mole HCl: From stoichiometry, 6 mol HCl produces 3 mol H₂, so 1 mol HCl produces 0.5 mol H₂ = 11.2 L at STP. TRUE
(2) Per 1 mole Al: 2 mol Al produces 3 mol H₂, so 1 mol Al produces 1.5 mol H₂ = 33.6 L at STP only, not regardless of T and P. FALSE
(3) Volume ratio at same T,P: 6 mol HCl : 3 mol H₂ = 2:1, so 12 L HCl : 6 L H₂. TRUE
(4) Per 1 mole Al: 1.5 mol H₂ = 33.6 L, not 67.2 L. FALSE
Option (1) is correct.
Hence, the correct answer is option: 'A'.