Question

How do you find how much heat (in joules/g) is released by the combustion of something?

I have the values for mass of water, heat compacity of water, change in temperature, and total energy released in kJ.

Answer 1

heat=heat capacity * moles*change in temp in K

Answer 2

if your heat capacity if for g instead of moles then use grams instead of moles!

Answer 3

Enthalpy of combustion is the enthalpy change when one mole of a substance is completely burnt in excess of oxygen. when (something) releases heat it is an exothermic reaction, therefore you should use :\[\Delta H = -cpm \Delta T\] it is always better to write down the chemical Equation . When something is burnt in axcees oxygen it originates carbon dioxide + water, and you should be able to balance the equation.
After you use the equation above, you should take in consideration the mass of (something) using : \[mol =\frac{ mass }{ molar mass (something) }\] of course you should take the number of the mol from your chemical equation, see how much moles moles of the (something) has in relation with water (H2O).
I hope it helps .
(sorry my english)
Radiation......