Question

The complete combustion of a sample of coal in a bomb calorimeter (in which the contents are at constant volume) releases 16.0 kJ of heat and raises the temperature of the calorimeter by 2.22°C. What is the heat capacity of the calorimeter? The heat capacity of a calorimeter (calorimeter constant) can be calculated using the following equation: qrxn = −Ccal × ΔT, where qrxn is the amount of heat released or absorbed by the reaction mixture, Ccal is the heat capacity of the calorimeter, and ΔT is the temperature change in °C or K. kJ/°C

Answer 1

Answer: $7.21kJ/^0C$

Explanation:

Total heat released during reaction is equal to total heat gained by water and bomb calorimeter.

Let the heat released during reaction be q.

q = -16.0 kJ

Thus heat absorbed by calorimeter = + 16.0 kJ

$q_{cal}=c_{cal}\times \Delta T$

$q_{cal}$ = Heat gained by calorimeter = 16000 J

$c_{cal}$ = Heat capacity of calorimeter = ?

Change in temperature = ΔT = 2.22°C

$16000J=c_{cal}\times 2.22^0C$

$16000J=c_{cal}\times 2.22^0C$

$c_{cal}=\frac{16.0J}{2.22^0C}=7.21kJ/^0C$

Thus heat capacity of a calorimeter is $7.21kJ/^0C$