Question

write the equation for heat transfer for melting/freezing phase change and define all the variables.

write the equation for heat transfer for vaporization/condensation phase change and define all the variables.

Explanation:

1. For melting/freezing phase change, the heat transfer depends on the mass of the substance and its specific latent heat of fusion, which is the energy per unit mass needed to change between solid and liquid states.
2. For vaporization/condensation phase change, the heat transfer depends on the mass of the substance and its specific latent heat of vaporization, which is the energy per unit mass needed to change between liquid and gas states.

Answer:

1. Heat Transfer for Melting/Freezing Phase Change:

Equation: $Q = m \cdot L_f$
Variable Definitions:

• $Q$: The total heat transferred during the phase change (units: joules, J)
• $m$: The mass of the substance undergoing the phase change (units: kilograms, kg)
• $L_f$: The specific latent heat of fusion of the substance, the amount of heat per unit mass required to melt (or released to freeze) the substance without changing temperature (units: joules per kilogram, J/kg)

1. Heat Transfer for Vaporization/Condensation Phase Change:

Equation: $Q = m \cdot L_v$
Variable Definitions:

• $Q$: The total heat transferred during the phase change (units: joules, J)
• $m$: The mass of the substance undergoing the phase change (units: kilograms, kg)
• $L_v$: The specific latent heat of vaporization of the substance, the amount of heat per unit mass required to vaporize (or released to condense) the substance without changing temperature (units: joules per kilogram, J/kg)