Heat & Temperature of Phase Changes

[Angela Wu-2H]

Under my class notes, it states "Because heat is required during melting or boiling (phase transitional), the temperature of the sample remains constant even though heat is being supplied."

Is this basically saying temperature stays constant because the heat required cancels out with the heat being supplied? What guarantees that the exact same amount of heat required is the exact same amount of heat that is being supplied?

[Wilson 2E]

At a temperature where phase change occurs, heat energy is being used to separate molecules rather than change the temperature of the substance, resulting in a constant temperature.

[305385703]

There is no set rate of how much heat is being used to change phase. There is a certain amount of heat that is required to change phases, and once that amount of heat is inputted into the substance, it changes phase and any more heat added contributes to the temperature.

[Isabella Dal Porto 1H]

When there is a phase change, temperature remains constant for a period of time because all the heat added is being used to break bonds.

[Callum Guo 1H]

It takes energy to change phases. (heat of vaporization, heat of fusion)

[405268063]

If you look at the graph Dr. Lavelle drew of q versus T early on in thermochemistry, you can see that at the phase changes, the graph plateaus.