Phase Changes and Heat

[Brandon Yu]

Why does the temperature not rise during a phase change?

[Emma Kelly 3L]

I believe it's because the energy that would normally contribute to the rise in temperature is being used to break the bonds necessary for the phase change. I'm not quite sure though.

[Naman Jain 3F]

I believe the previous answer follows what Dr. Lavelle said in lecture, the extra energy being put into the system is going into breaking the bonds required for a phase change, not into increasing the kinetic energies of the particles, which results in no temperature increase.

[Kiana Rogers 1E]

During a phase change, the supplied energy is not used to increase the kinetic energy of the molecules, but to change the binding energies. Therefore, the temperature remains constant.

[Akane Shimoyoshi 3F]

Temperature doesn't change during a phase change because the added heat is used to increase the kinetic energy of molecules. Any heat beyond what is necessary to excite the molecules into a different phase would be in excess, and that is when temperature starts to increase.

[Joseph Ettipio]

Temperature doesn't rise during a phase change because instead of energy increasing the kinetic motion/vibration of the atoms in whatever material you're changing the phase of, the energy is going into breaking certain bonds so that the phase can change at all. So liquid water being raised to a boil on a molecular level will see its molecules vibrate more vigorously as it approaches its boiling point. However, when that liquid water has reached its boiling point, on the molecular level the vibration will remain constant, but bonds will begin to break in order for the liquid water to turn into water vapor.

[Vincent Real 2C]

During a phase change, the energy given by temperature is channeled into the intermolecular forces between molecules. This is necessary, as the breaking of bonds between molecules is what causes a molecules phase to change. Once this process is finished, however, the energy is re-channeled into increasing the temperature of the environment.

[Melody Khoshneviszadeh 3C]

when energy is added to a system it is used to do work such as break bonds and the rest is released as heat. during phase changes the heat is primarily used to break bonds and form bonds in the substance and as a result, not much energy is left to be released as heat which means the temperature does not change during that transitional period.

[Misha_Khan_2H]

The energy going into the system is being used to break the chemical bonds of molecules involved, so it does not contribute to increase in the temperature of the system.

[Cecilia Lei 3K]

Because the energy is added to turn the phase from one to the other.

[Viduttam Dutt 2H]

Any and all energy that is being introduced into a system that is undergoing a change in phase is devoted to breaking the bonds between the molecules in that state. Upon gaining more energy, particles can break free of intermolecular forces of attraction and undergo a change of state.

[Anubhav_Chandla1G]

Similar to what everyone has stated before, since the energy being added is being used to alter the structure binding state, increased energy does not contribute to increased temperature change.