Sulfuric acid dissociation in solution

Steps:

• Sulfuric acid (H₂SO₄) dissociates in water: complete first step (H₂SO₄ → H⁺ + HSO₄⁻), partial second step (HSO₄⁻ ⇌ H⁺ + SO₄²⁻), leaving some undissociated H₂SO₄.
• Total sulfur atoms remain 1 mole from 1 mole H₂SO₄, regardless of ionization.
• H⁺ ions total nearly 2 moles (1 full + partial), but SO₄²⁻ ions are less than 1 mole.
• SO₄²⁻ ion has -2 charge (equivalent to 2 excess electrons per ion), but total electrons far exceed that.

Why D is correct:

• D identifies the accurate statement among options, as A overstates sulfur atoms by ignoring forms, per Avogadro's number for total atoms.

Why the others are wrong:

• A: Solution has exactly 6.02 × 10²³ sulfur atoms total, but statement ignores distribution across species.
• B: H⁺ exceeds SO₄²⁻ due to partial second dissociation, violating charge balance.
• C: One mole SO₄²⁻ has ~3.86 × 10²⁵ total electrons (from atomic structure), not 2 moles; charge equivalence ≠ total electrons.

Final answer: D