Question

The heat capacity of a bomb calorimeter wasdetermined by burning 6.79 g of methane (energy of combustion =-802 kJ/mol CH₄) in the bomb. The temperature changedby 10.1°C.

A. What is the heatcapacity of the bomb?
B. A 12.6 g sample of acetylene (C₂H₂)produced a temperature increase of 18.3°C in the same calorimeter. What is the energy of combustion of acetylene (in kJ/mol)?

Answer 1

To find the bomb calorimeter's heat capacity, we use the heat of combustion of methane and the temperature change. For acetylene's energy of combustion, we use the calorimeter's heat capacity and the temperature change caused by burning acetylene.

Step-by-step explanation:

To calculate the heat capacity of the bomb calorimeter, we use the formula q = C × ΔT, where q is the heat absorbed or released, C is the heat capacity, and ΔT is the change in temperature. Knowing that 6.79 g of methane has an energy of combustion of -802 kJ/mol, and the temperature change was 10.1°C, we can calculate the heat capacity of the bomb after calculating the total amount of heat released using the molar mass of methane (16.04 g/mol).

For part B, to find the energy of combustion of acetylene, we first need to determine the total heat absorbed by the calorimeter using the already found heat capacity, with the given temperature change of 18.3°C. Then, we convert the heat absorbed to kJ/mol using the molar mass of acetylene (26.04 g/mol).