Final answer:
Using the heat of combustion of benzoic acid (26.38 kJ/g), and the mass of the acid (5.000 g), the total heat released was calculated (-131.90 kJ) and used along with the temperature increase (18.00 °C) to determine the calorimeter's heat capacity, which is 7.33 kJ/°C.
Step-by-step explanation:
To calculate the heat capacity of the calorimeter (Cbomb), we can use the combustion information of benzoic acid. Given that the combustion of benzoic acid releases 26.38 kJ of heat per gram, and the mass of benzoic acid is 5.000 g, we first calculate the total heat released (qcomb) during the combustion:
qcomb = mass × ΔHcomb
= 5.000 g × (-26.38 kJ/g)
= -131.90 kJ
Next, we determine the heat capacity of the calorimeter using the formula:
Cbomb = -qcomb / ΔT
= -(-131.90 kJ) / 18.00 °C
= 7.33 kJ/°C
The negative sign in front of qcomb is because heat released from the substance is absorbed by the calorimeter, which causes the increase in temperature.