General Chemistry

Question

A gaseous fuel mixture contains 22.8% methane (CH4), 40.0% ethane (C2H6) and the rest propane (C3H8) by volume.

When the fuel mixture contained in a 1.55 L tank, stored at 748 mmHg and 298 K, undergoes complete combustion, how much heat is emitted? (Assume that the water produced by the combustion is in the gaseous state.)

Answer 1

Volume CH4 = 22.8% x 1.55 L = 0.353 L

Volume C2H6 = 40.0% x 1.55 L = 0.620 L

Volume C3H8 = 1.55 L - 0.353 L - 0.620 L = 0.577 L

Use PV - nRT to convert each to moles (P=0.984 atm; V= L of each gas; R=0.0821 Latm/Kmol; T=298K)

Once you have the moles of each gas, use ∆Hcombustion for each gas to find heat produced from each gas separately then add them up to get total heat produced.