[ByShine]

A bomb calorimeter has a heat capacity of 843J/C and contains 473g of water. If the combustion of 0.500 mole of a hydrocarbon increases the temperature of the calorimeter and contents from 22.73C to 26.95C determine the heat evolved per mole of hydrocarbon.

My attempt at this question :

qcal = ccal * dT ( change in temperature )
qcal = (843 J/C)(4.22 c) = 3557 Joules ( one extra sig fig for decimal calculation later on )

and from here I would just divide 3557 joules by 0.500 mole but this is not the correct way to do it. My senses tell me that I'd have to use the grams of water or the moles given, but I do not know how to solve this question the right way..
since bomb calorimeter does not take sense for grams given by the equation.. i dont know what else i can do to get the answer

[opti384]

The heat that was emitted from the reaction was absorbed both by water and the calorimeter.

[ByShine]

The heat that was emitted from the reaction was absorbed both by water and the calorimeter.

So what would I do with that? that's what im wondering

[opti384]

I see that you calculated the heat absorbed by the calorimeter. Then why not do the same thing for water? Water inside the calorimeter also absorbed the heat from the reaction you know.

[ByShine]

So for water, q=(473 g)(4.18 J/g x c)(4.22 C) gave me 8344 joules

[opti384]

Don't forget that you need to determine the heat evolved per mole.

[ByShine]

8344/0.500

16688 joules/mol

3557/0.500

7114 joules/mol

adding it gives me 23803 joules / mol

is that the answer?