What exactly is heat of combustion? How would I calculate it?

[black_hole]

1. Calculate heat of combustion for butane. Given:

mass water- 129.91g
mass butane 0.15g
old temp- 16.4 degrees C
new temp.- 26.7 degrees C

2. Homework Equations

2C4H10 + 3O2 yields 8CO2 + 10H2O

3. The Attempt at a Solution

I've tried, but I really have no idea. I only know how to calculate q and apparently that's not the same.

 

[Borek]

Heat of combustion is per mole, what you have calculated is for 0.15g...