Limiting reactant in catalytic converter reaction

Steps:

• Reaction: 2NO + 2CO → N₂ + 2CO₂; molar masses NO=30 g/mol, CO=28 g/mol.
• Moles: NO = 23/30 ≈ 0.767 mol; CO = 7/28 = 0.25 mol.
• Limiting reactant CO (0.25/2 = 0.125 reaction units); produces 0.125 mol N₂ + 0.25 mol CO₂ = 0.375 mol total gas.
• At room conditions (RTP, 24 dm³/mol), volume = 0.375 × 24 = 9.0 dm³.

Why C is correct:

• Matches total product moles (0.375) × molar volume (24 dm³/mol) from ideal gas law at RTP.

Why the others are wrong:

• A: Assumes only N₂ volume, ignoring CO₂.
• B: Uses CO moles directly without stoichiometry.
• D: Assumes excess NO reacts fully, overestimating products.

Final answer: C