Heat of Combustion Candle Wax Calorimetry

[Lancer232]

Homework Statement

I'm supposed to find the heat of combustion for candle wax (which was used to boil water in a simple calorimeter), yet I have no clue on how to do it, the lab books at school do not tell anything about the calorimeter's specific heat or give a formula for heat of combustion. So far I have my final temperature at 42.0 degrees Celsius, mass of 97.00g (after melting, with base), 1850 cal/g degrees Celsius absorbed by the can (formula used was Cal=mass H2O X Temperature Change H2O X Specific Heat of Water). My mass of H2O was 50g (assuming 1 ml is 1g, unless I got that backwards and its 1mg, I never really understood a few parts of the lab). The mass of my wax is 0.20g (97.20g - 97.00g).

Homework Equations

All I know is the candle wax's formula, C₃₆H₇₄
We aren't allowed to take the lab books home, and my data table is brief and straight to the point, the way my teacher wants it to be. I could figure it out on my own if I just get the formula, unless I forget something.

 

[mgb_phys]

First you need to know how much energy you got from the candle.
For that you need the mass of water (yes 1g=1cc) the specific heat capacity of water and the temperature change (we will ignore the container)

Be careful of the units - it's probably best to convert everything in kg and J.
You have the specific heat slightly confused. Water has a specific heat capcity of around 4200J/kg/degree or 1cal/g/degree

then you can quote the heat of combustion for the candle either in J/kg or since you are given the formula you could work out how many moles and give it as J/mol.