[tex] C_{3} H_{8} + 5 O_{2} ---\ \textgreater \ 3CO_{2} +4H_{2}O (-2012 \frac{kJ}{mol} )
3 mol 10 mol
C_{3}H_{8} is /excess /reactant
because 3 mol propane require 15 mol oxygen (by reaction)
5 mol oxygen ---1 mol propane, so
10 mol oxygen ---2 mol propane
Only 2 mole propane will be burned,
so
2012 ( kJ/mol)*2 mol =4024 KJ heat will be given off
Correct answer is number 4.
[/tex]