What is the final temperature of the calorimeter contents?

Question

A bomb calorimeter whose components have a heat capacity of 6.66 kJ/°C is filled with 943 g of water. The initial temperature of the calorimeter contents is 21.61°C. A 1.144 g sample of benzoic acid (Ecomb = -26.42 kJ/g) is combusted in the calorimeter. What is the final temperature of the calorimeter contents?

Answer 1

Benzoic acid is C6H5COOH

On combustion it will give,

C6H5COOH + 15/2 O2 -> 7CO2 + 3H2O

Molar mass of C6H5COOH is 78+44 = 122 g

So, 1.144g will give 1.144*3*18/122 g of H2O

= 0.506 g

Thus heat released = 26.42*1.144 kJ

Let final temp be T

So, (0.9435*4184*(T-21.61)+6.66*(T-21)) = 26.42*1.144

So, T = 21.007 deg C