Calorimeters are used to determine which property?

• A. Temperature change
• B. Specific heat capacity
• C. Enthalpy of a reaction
• D. Activation energy

Answer: (B)

Calorimeters measure heat flow by tracking the temperature change of a known mass. The key relation is q = m c ΔT, which links the amount of heat transferred to how much the temperature of a substance changes. From a calorimetric measurement, you can determine the specific heat capacity c by rearranging c = q / (m ΔT). In other words, by measuring how much heat is exchanged and how much the temperature rises for a known mass, you directly obtain how well that substance stores heat—their specific heat capacity.

While you can, in principle, use calorimetry to infer enthalpy changes for reactions (by measuring the heat at constant pressure), the straightforward, direct outcome of a simple calorimetric measurement on a substance is its capacity to absorb heat per degree of temperature change. Activation energy, on the other hand, is determined from rate data, not from heat measurements alone.