A substance has a heat of vaporization of Hvap and heat of fusion of Hfus. Express the heat of sublimation in terms of Hvap and Hfus.

The heat of vaporization represents the amount of energy required to transform a substance from its liquid state to its gaseous state at a given pressure, typically atmospheric pressure. This energy overcomes the attractive forces between particles in the liquid, allowing them to spread out and form a gas.

The concept is fundamental when studying the energy changes involved in phase transitions. For example, when water is boiled, it absorbs a significant amount of energy to turn into steam. This energy is called the heat of vaporization, and every substance has a unique value for it. Understanding this concept is crucial for various applications, including the refrigeration cycle and predicting weather patterns.

In contrast to vaporization, the heat of fusion concerns the phase change from solid to liquid. It is the energy required to melt a solid substance at its melting point without changing its temperature.

This energy is utilized to break the organized structure of a solid into a less ordered liquid state. Similar to the heat of vaporization, the heat of fusion is unique to each substance. For instance, the melting of ice to water requires an input of energy to loosen the structured hydrogen bonds entreating water molecules, embodying the heat of fusion for water.

Phase transitions refer to the transformation of a substance from one state of matter—solid, liquid, or gas—to another. These transitions include melting (fusion), freezing, vaporization, condensation, sublimation, and deposition.

Each phase transition involves energy changes, either absorbing or releasing energy. For example, when a solid becomes a liquid, it absorbs energy (heat of fusion), and when a gas condenses to a liquid, it releases energy. Understanding phase transitions is vital in fields such as meteorology, engineering, and materials science.