Question

A bomb calorimeter can be used to measure the energy change of a chemical reaction. A 0.025 gram sample of a fuel is burned and found to produce 3040 J of heat. Which statement is correct?

A) The enthalpy of combustion is only 1 kJ per gram.
B) The fuel must be a solid material, as only solids can be burned in a calorimeter.
C) The enthalpy of combustion is 152 kJ per gram.
D) The enthalpy of combustion is 152 kJ per mole.
E) The reaction is endothermic.

Answer 1

The enthalpy of combustion is 152 kJ per gram.

Step-by-step explanation:

The bomb calorimeter is used to measure the energy change of a chemical reaction. In this case, a 0.025 gram sample of fuel produced 3040 J of heat. To determine the correct statement, we need to calculate the enthalpy of combustion. The enthalpy of combustion is the amount of heat released when one gram of fuel is burned.

To calculate the enthalpy of combustion, we divide the amount of heat produced by the mass of the fuel. In this case, the mass of the fuel is 0.025 grams. Therefore, the enthalpy of combustion is 3040 J / 0.025 g = 121600 J/g.

Since the question asks for the enthalpy of combustion per gram, the correct statement is (C) The enthalpy of combustion is 152 kJ per gram. This is because 121600 J/g is equal to 121.6 kJ/g.