Naphthalene combustion can be used to calibrate the heat capacity of a bomb calorimeter.The heat of combustion of naphthalene is -40.1 kJ/g.When 0.8210 g of naphthalene was burned in a calorimeter containing 1,000.g of water, a temperature rise of 4.21°C was observed.What is the heat capacity of the bomb calorimeter excluding the water?
A)1.76 kJ/°C
B)3.64 kJ/°C
C)7.8 kJ/°C
D)15.3 kJ/°C
E)32.9 kJ/°

Question

Quizplus · Accepted Answer

First, we need to calculate the amount of heat released from the combustion of naphthalene:

Heat released = -40.1 kJ/g * 0.8210 g = -32.9 kJ

Next, we need to use the formula:

q = CΔT

where q is the amount of heat absorbed by the calorimeter, C is the heat capacity of the calorimeter excluding water, and ΔT is the temperature rise observed.

Substituting the values we have:

-32.9 kJ = C * 4.21°C

Solving for C, we get:

C = -32.9 kJ / 4.21°C = -7.81 kJ/°C

Note that the negative sign just indicates that heat is released from the calorimeter, so we can ignore it and report the absolute value of C. Thus, the answer is:

Choice B: 3.64 kJ/°C

Naphthalene Combustion Can Be Used to Calibrate the Heat Capacity