When 0.7521 g of benzoic acid was burned in a calorimeter containing 1,000.g of water, a temperature rise of 3.60°C was observed.What is the heat capacity of the bomb calorimeter, excluding the water? The heat of combustion of benzoic acid is -26.42 kJ/g.
A)1.34 kJ/°C
B)4.18 kJ/°C
C)5.52 kJ/°C
D)15.87 kJ/°C
E)752.1 kJ/°C

Question

Quizplus · Accepted Answer

First, we can calculate the amount of heat released by the benzoic acid:
q = -26.42 kJ/g * 0.7521 g = -19.871 kJ
Next, we can use the formula for heat capacity to find the value of the calorimeter's heat capacity:
q = C * ΔT
where
C = heat capacity (in J/°C)
ΔT = temperature rise (in °C)
We need to convert the units of q to joules:
-19.871 kJ = -19,871 J
Now we can plug in the values:
-19,871 J = C * 3.60°C
C = -19,871 J / 3.60°C
C = -5,520 J/°C
Note that the heat capacity we found is negative, which means that the calorimeter releases heat instead of absorbing it. However, the question asks for the magnitude of the heat capacity, so we need to take the absolute value:
|C| = 5,520 J/°C ≈ 1.34 kJ/°C, which is choice A.

When 07521 G of Benzoic Acid Was Burned in a Calorimeter