Many portable gas heaters and grills use propane, C3H8(g).

Using enthalpies of formation, calculate the quantity of heat produced when 16.0g of propane is completely combusted in air under standard conditions. Assume that liquid water is forming.

4 answers

C3H8 + 5O2 ==> 3CO2 + 4H2O

dHrxn = (n*dHf products) - (n*dHf reactants). Let's say dHrxn = x and that is the heat of combustion. You can get the dHf values from your text or notes.

So you can get x kJ of heat from 44 g (1 mole from the equation) C3H8. How much heat can you get from 16.0g.
That's x kJ x (16.0/44.0) = ? kJ for 16.0 g propane.
69^4
-806 kJ
805