Final answer:
The question is related to Chemistry and involves measuring energy changes during a chemical reaction, known as enthalpy change (ΔH), using thermochemical equations and calorimetry.
Step-by-step explanation:
The subject of this question is clearly Chemistry. The question involves understanding the energy change that occurs during a chemical reaction, which is a key concept in the field of chemistry, especially within thermodynamics and physical chemistry. Chemists study these energy changes to determine whether a reaction is endothermic or exothermic by measuring the enthalpy change (ΔH).
To quantify these changes, chemists use a unit known as joules for the measurement of energy, though calories may also be used. The conversion between these two units is often needed in scientific calculations. Calorimetry is a technique that directly measures the heat changes associated with chemical reactions or physical changes.
Thermochemical equations are a vital tool for chemists. These equations not only provide information about the substances involved in reactions but also the enthalpy changes that accompany them. By performing an experiment or observation, a chemist denotes the reactive chemicals as the system and everything else as the surroundings. An enthalpy change can then be calculated, which reflects the energy transfer between the system and the surroundings according to the law of conservation of energy.