Solving for a gaseous reactant

Question

Write a balanced chemical equation, including physical state symbols, for the combustion of liquid hexane in to gaseous carbon dioxide and gaseous water.

 

Suppose 0.260 kg of hexane are burned in air at a pressure of exactly 1 atm and a temperature of 15.0 C. Calculate the volume of carbon dioxide gas that is produced.

Answer 1

2C₆H₁₄₍l) + 19O₂(g) ==> 12CO₂(g) + 14H₂O(l) assuming COMPLETE combustion

moles of C₆H₁₄ present = 0.260 kg x 1000 g/kg x 1 mole/86.18 g = 3.017 moles

moles CO₂ produced = 3.017 moles C₆H₁₄ x 12 moles CO₂/2 moles C₆H₁₄ = 18.10 moles

volume of CO₂ can be calculated from PV = nRT and V = nRT/P

V = (18.10 mol)(0.0821 L-atm/K-mol)(288K)/1 atm

V = 428 liters = 400 liters (to 1 significant figure)