What is measured in a calorimeter during a chemical reaction?

In a calorimeter, the primary measurement taken during a chemical reaction is the temperature change associated with the reaction. This change in temperature allows for the calculation of the heat absorbed or released by the reaction, known as enthalpy change. When a reaction occurs, it often either absorbs heat from the surroundings or releases heat into the surroundings, which directly affects the temperature of the solution in the calorimeter.

By monitoring how much the temperature increases or decreases, one can use the specific heat capacity of the solution and the mass of the substance to quantify the heat exchanged. This information is crucial in thermodynamics and helps understand the energy changes involved in chemical reactions.

Other aspects, such as the concentration of products, gas emissions, or the mass of solid reactants, are not directly measured in a calorimeter. These factors may indirectly influence the results or be of interest in different experimental setups, but they do not provide the immediate thermal data that calorimetry is designed to capture.