Stoichiometric ratio in SO2 formation

Steps:

• Molar mass of S is 32 g/mol, so 16 g S = 16/32 = 0.5 mol S.
• SO2 formula shows 1 mol S reacts with 1 mol O2 (2 O atoms).
• Thus, 0.5 mol S requires 0.5 mol O2.
• Molar mass of O2 is 32 g/mol, so 0.5 mol O2 = 0.5 × 32 = 16 g.

Why C is correct:

• Law of definite proportions requires fixed 1:1 molar ratio of S to O2 in SO2, and equal molar masses (32 g/mol each) yield equal masses for equal moles.

Why the others are wrong:

• A: 4 g equals 0.25 mol O2, insufficient for 0.5 mol S (only one O atom equivalent).
• B: 8 g equals 0.25 mol O atoms, half the required oxygen.
• D: 32 g equals 1 mol O2, twice the amount needed for 0.5 mol S.

Final answer: C