Gas volume ratios from balanced equation

Steps:

• Balanced equation: 2H₂S produces 2SO₂, so mole ratio of H₂S to SO₂ is 1:1.
• At room temperature and pressure, equal volumes of gases contain equal moles (Avogadro's law).
• Volume ratio of H₂S to SO₂ is therefore 1:1.
• For 48 dm³ H₂S, volume of SO₂ = 48 dm³.

Why C is correct:

• 1:1 volume ratio from equal coefficients for H₂S and SO₂ in the equation, per Avogadro's law.

Why the others are wrong:

• A: Assumes 2:1 ratio (SO₂ half of H₂S), reversing the coefficients.
• B: Confuses with O₂ ratio (3:2), yielding 3/4 of H₂S volume.
• D: Assumes 1:2 ratio (SO₂ double H₂S), inverting the equal coefficients.

Final answer: C