A substance is dissolved in water, and the temperature of the surroundings decreases. Is this process exothermic or endothermic? Explain your reasoning in 3-4 sentences.
This process is endothermic. When a substance dissolves in water, energy is required to break the bonds between the particles of the substance. As the temperature of the surroundings decreases, it implies that energy is being absorbed from the surroundings to break these bonds and dissolve the substance. Consequently, the process is endothermic as it requires an input of energy.
To determine whether the process is exothermic or endothermic, we need to understand the concepts of exothermic and endothermic reactions. In an exothermic process, energy is released to the surroundings, resulting in an increase in temperature. In an endothermic process, energy is absorbed from the surroundings, leading to a decrease in temperature.
In this case, since the temperature of the surroundings decreases, it indicates that energy is being absorbed from the surroundings. Therefore, the process of dissolving the substance in water is an endothermic process. The energy needed to break the intermolecular forces between the solute particles and to overcome the energy barrier for dissolving are supplied by the surroundings, resulting in a decrease in temperature.