Reaction rate increases with acid concentration, but total hydrogen volume is identical

Steps:

• Calculate moles: 2.4 g Mg is 0.1 mol; Exp 1 has 0.1 mol H₂SO₄ (100 cm³ × 1.0 mol/dm³), Exp 2 also 0.1 mol (50 cm³ × 2.0 mol/dm³).
• Determine total product: Stoichiometry gives 0.1 mol H₂ (2.24 dm³ at RTP) for both, so same maximum volume.
• Analyze rate: Reaction rate ∝ [H⁺]; Exp 2's 2.0 mol/dm³ acid yields faster initial rate than Exp 1's 1.0 mol/dm³.
• Predict graph: Both curves reach same volume, but Exp 2 is steeper and plateaus sooner.

Why A is correct:

• Matches rate law (rate = k [H₂SO₄]), showing identical total H₂ but faster kinetics for higher concentration.

Why the others are wrong:

• B: Incorrectly shows different maximum volumes, ignoring equal moles of reactants.
• C: Depicts identical rates, violating concentration dependence.
• D: Reverses curves, with lower concentration faster.

Final answer: A