Name the phase transition in each of the following situations and indicate whether it is exothermic or endothermic.
(a) Frost appears on a window on a cold winter day.
Is frost considered a liquid? I am really confused
thanks:)
freezing. frost is a ice form
The phase transition that occurs when frost appears on a window is called deposition, and it is an exothermic process.
Frost is not considered a liquid but a solid. It is formed when water vapor in the air directly changes into ice crystals without first becoming a liquid. This process is known as deposition.
To understand why deposition is exothermic, we need to look at the energy changes that occur during the process. When water vapor comes into contact with a cold surface, such as the window pane on a cold winter day, it loses energy (heat) to that surface. The decreased energy causes the water vapor molecules to slow down and come closer together. As a result, they undergo a phase transition and change into solid ice crystals directly, skipping the liquid phase.
This release of heat energy during the transition from water vapor to ice is what makes deposition an exothermic process. It is the opposite of sublimation, which is the phase transition from solid to gas (such as dry ice turning into carbon dioxide gas), which is endothermic because it requires the input of energy.