Which statement about bomb calorimetry is true?

• A. Bomb calorimetry requires the reaction to occur in an open container.
• B. Bomb calorimetry is used to determine the enthalpy change (ΔH) directly.
• C. Bomb calorimetry measures the change in internal energy (ΔU) of a reaction at constant volume.
• D. Bomb calorimetry is performed at constant pressure.

Answer: (C)

Verified step by step guidance

1. Understand that bomb calorimetry is a technique used to measure the heat released or absorbed during a chemical reaction, typically combustion, in a sealed, rigid container called a bomb.
2. Recognize that the bomb calorimeter operates at constant volume because the reaction occurs in a sealed container that does not allow expansion or compression.
3. Recall the thermodynamic relationship that at constant volume, the heat exchanged corresponds to the change in internal energy (ΔU) of the system, not the enthalpy change (ΔH).
4. Note that enthalpy change (ΔH) is measured under constant pressure conditions, which is not the case in bomb calorimetry.
5. Conclude that the true statement is: Bomb calorimetry measures the change in internal energy (ΔU) of a reaction at constant volume.