Final answer:
To determine the heat capacity (calorimeter constant) of a bomb calorimeter, a known compound with a known enthalpy of combustion can be used. By burning a carefully weighed mass of the compound in the calorimeter and measuring the temperature change, the heat capacity can be calculated using the formula Cbomb = Q / ΔT. In this case, the heat capacity of the calorimeter is approximately -6.08 kJ/°C.
Step-by-step explanation:
The heat capacity (calorimeter constant) of a bomb calorimeter can be determined using a known compound with a known enthalpy of combustion. By burning a carefully weighed mass of a standard compound, such as benzoic acid, in the bomb calorimeter and measuring the temperature change, we can calculate the heat capacity of the calorimeter. The formula to calculate the heat capacity (Cbomb) is:
Q = Cbomb * ΔT
where Q is the heat released, Cbomb is the heat capacity of the calorimeter, and ΔT is the change in temperature. To solve for Cbomb, we can rearrange the formula:
Cbomb = Q / ΔT
In this case, the heat of combustion of the compound is -3550.0 kJ/mol, and when 1.075 g of the compound is burned, the temperature of the calorimeter rises by 4.073 ∘C. To calculate Cbomb, we need to convert the mass of the compound to moles:
moles = mass / molar mass = 1.075 g / 154.74 g/mol = 0.00694 mol
Now, we can calculate the heat released:
Q = moles * heat of combustion = 0.00694 mol * -3550.0 kJ/mol = -24.76 kJ
Finally, we can calculate the heat capacity of the calorimeter:
Cbomb = Q / ΔT = (-24.76 kJ) / (4.073 °C) = -6.08 kJ/°C
Therefore, the heat capacity (calorimeter constant) of the calorimeter is approximately -6.08 kJ/°C.