Hi all! Here's a question I've been struggling with for a few hours:

A typical composition of natural gas could be 90% methane, 8% ethane and 2% propane (mol). Under standard conditions for temperature and pressure, the complete combustion of 11.2 m

^{3} of natural gas produces, approximately, the following mass of CO

_{2}:

a) 22.4 kg

b) 11.2 kg

c) 32.6 kg

d) 24.6 kg

Letter d is the correct answer. This is what I did:

1 mol of any gas occupies the volume of 22.4 L. Therefore, 11.2 m

^{3} is equal to 500 mol of natural gas. So I wrote the chemical equation:

1 CH

_{4} + 1 C

_{2}H

_{6} + 1 C

_{3}H

_{8} + 21/2 O

_{2} 6 CO

_{2} + 9 H

_{2}O

Considering the proportions, 1 mol of natural gas produces 6 mol of CO

_{2}. So 500 mol produces 3000 mol of CO

_{2}, which is equivalent to 132 kg.

What am I doing wrong here?