The enthalpy of combustion of benzoic acid (c6h5cooh) is commonly used as the standard for calibrating constant-volume bomb calorimeters; its value has been accurately determined to be −3226.7 kj/mol. when 2.8161 g of benzoic acid are burned in a calorimeter, the temperature rises from 21.84°c to 24.67°c. what is the heat capacity of the bomb? (assume that the quantity of water surrounding the bomb is exactly 2250 g.)

Answer : The heat capacity of the bomb calorimeter

Explanation :

First we have to calculate the heat released by the combustion.

where,

q = heat released by combustion = ?

n = moles of benzoic acid =

= enthalpy of combustion = 3226.7 kJ/mole

Now put all the given values in the above formula, get:

Now we have to calculate the heat capacity of the bomb calorimeter.

Heat released by the reaction = Heat absorbed by the calorimeter + Heat absorbed by the water

where,

q = heat released by the reaction  = 74.4077 kJ = 74407.7 J

= heat absorbed by the calorimeter

= heat absorbed by the water

= specific heat of calorimeter = ?

= specific heat of water =

= mass of water = 2550 g

= change in temperature =

Now put all the given values in the above formula, we get:

Therefore, the heat capacity of the bomb calorimeter