Stoichiometry of carbon monoxide combustion by mass One kilogram of carbon monoxide (CO) requires 4/7 kg of oxygen (O2) for complete oxidation. The complete reaction produces which mass of carbon dioxide (CO2)?

Introduction / Context:
Combustion stoichiometry connects mass of reactants to mass of products using balanced chemical equations and molar masses. This problem tests your ability to translate a known oxygen requirement into the corresponding product mass.

Given Data / Assumptions:

• Reaction: 2 CO + O2 → 2 CO2 (complete oxidation).
• Given mass ratio: 1 kg CO needs 4/7 kg O2.
• Molar masses: CO = 28 kg/kmol, O2 = 32 kg/kmol, CO2 = 44 kg/kmol.

Concept / Approach:
Use the balanced equation to derive proportional mass relationships. For 2 mol CO (56 kg) reacting with 1 mol O2 (32 kg), products are 2 mol CO2 (88 kg). Scale linearly to 1 kg CO to find the produced CO2 mass.

Step-by-Step Solution:
From 56 kg CO → 88 kg CO2.Therefore, per 1 kg CO: CO2 produced = 88/56 kg = 11/7 kg.Given O2 requirement per 1 kg CO is 32/56 = 4/7 kg, which is consistent with the statement.Hence the correct product mass is 11/7 kg CO2.

Verification / Alternative check:
Mass conservation: Inputs 1 kg CO + 4/7 kg O2 = (7/7 + 4/7) kg = 11/7 kg total; output is 11/7 kg CO2, confirming balance.

Why Other Options Are Wrong:

• 11/3 kg: too large; violates mass conservation for the given inputs.
• 7/3 kg or 8/3 kg of CO: lists CO as a product; complete oxidation produces CO2, not CO.
• 1 kg CO2: ignores added oxygen mass.

Common Pitfalls:
Forgetting to use molar mass ratios or neglecting oxygen contribution to product mass.

Final Answer:
11/7 kg of carbon dioxide gas