In problems involving heat of vaporization, the equation Q=mcΔT is used for calculating heat during temperature changes within a single phase, while Q=mLv is applied during phase transitions at constant temperature. When transitioning from an initial temperature (T1) to a final temperature (T2) that includes a phase change, the calculations should be broken down into segments: heating the liquid from T1 to the transition temperature (Tt), applying the latent heat of vaporization, and then heating the gas from Tt to T2. The mLv equation is specifically used for the phase change. Understanding when to apply each formula is crucial for accurate calculations in thermodynamic problems.
