Question

Give examples for (a) liquid-to-gas, \((b)\) solid-to-liquid, (c) solid-to-gas, and \((d)\) gas-to-liquid mass transfer.

Short answer

Question: Provide an example of a mass transfer process for each of the following phase transitions: liquid-to-gas, solid-to-liquid, solid-to-gas, and gas-to-liquid. Answer: For liquid-to-gas phase transition, an example is evaporation, where water molecules gain energy and transition into vapor. For solid-to-liquid, an example is ice melting, where heat causes the ice to change into liquid water. For solid-to-gas, an example is sublimation, such as dry ice transitioning directly into a gaseous state. Finally, for gas-to-liquid, an example is condensation, where water vapor in the atmosphere cools down and forms water droplets, transitioning from a gaseous state to a liquid state.

Step-by-step solution

1. Liquid-to-gas mass transfer example

An example of liquid-to-gas mass transfer is the process of evaporation. When water in a pond, lake, or ocean is heated up by the Sun, the water molecules on the surface gain enough energy to overcome their liquid state attractions and become vapor. This transition from liquid water to water vapor results in mass being transferred from the liquid phase to the gas phase.

2. Solid-to-liquid mass transfer example

An example of solid-to-liquid mass transfer is the process of ice melting. When a block of ice is exposed to heat, its temperature increases, and its molecules gain enough energy to break their bonds in the solid state. As ice melts, it transitions from a solid to a liquid state, transferring mass between these two phases.

3. Solid-to-gas mass transfer example

An example of solid-to-gas mass transfer is the process of sublimation. When solid carbon dioxide, commonly known as dry ice, is exposed to atmospheric conditions, it directly transitions from a solid state to a gaseous state, without passing through the liquid phase. As the dry ice sublimates, mass is transferred from the solid phase to the gas phase.

4. Gas-to-liquid mass transfer example

An example of gas-to-liquid mass transfer is the process of condensation. When water vapor in the atmosphere cools down, it loses its energy and the molecules come closer together, transitioning from a gaseous state to a liquid state. This process forms water droplets, which can fall as precipitation. The mass of water is being transferred from the gas phase to the liquid phase during condensation.