When the combustion of 2.87 g of toluene is performed in a bomb calorimeter, the temperature rises from 20.05 °C to 44.15 °C. Given that the combustion of toluene, C7H8, has a ΔErxn of −3.50 x 10^3 kJ/mol C7H8, what is the heat capacity of the bomb calorimeter in kJ/°C?

• A. 9.78 kJ/°C
• B. 3.26 kJ/°C
• C. 6.52 kJ/°C
• D. 12.04 kJ/°C

Answer: (C)

Verified step by step guidance

1. First, calculate the number of moles of toluene (C7H8) combusted. Use the molar mass of toluene, which is approximately 92.14 g/mol. The formula to use is: \( \text{moles of toluene} = \frac{\text{mass of toluene}}{\text{molar mass of toluene}} \).
2. Next, determine the total energy change (q) for the reaction using the given \( \Delta E_{\text{rxn}} \) value. The formula is: \( q = \text{moles of toluene} \times \Delta E_{\text{rxn}} \).
3. Calculate the change in temperature (\( \Delta T \)) of the calorimeter using the initial and final temperatures: \( \Delta T = T_{\text{final}} - T_{\text{initial}} \).
4. The heat capacity (C) of the bomb calorimeter can be found using the formula: \( C = \frac{q}{\Delta T} \). Substitute the values of q and \( \Delta T \) into this formula.
5. Finally, compare the calculated heat capacity with the given options to identify the correct answer.