Heating curve in reverse

[Saaga Bergstrom 2E]

Based on the heating curve of water, the phase change from liquid to gas takes more energy than the phase change from solid to liquid. Is it true then that the phase change from gas to liquid releases more energy than the phase change from liquid to solid does? And is this the same amount of energy as going from liquid to gas but different sign?

[Elliana_Tsang_1L]

Yes, when calculating the energy for the reverse state change, it is the opposite sign with the same magnitude. It takes the same amount of energy to break the intermolecular forces (and/or intramolecular forces when dealing with reactions that break and form bonds) as the amount of energy released when intermolecular forces bring molecules together.

[Angie Tan 2L]

Yes, when reversing the reaction, the energy change is the same but with a different sign to it. This is because the energy that is required during the breaking of bonds is the same as the energy that is released during the forming of bonds.

[Nathan_Peng_3B]

I agree with the other answers, and wanted to add that the idea of released heat being the negative value of heat absorbed for the forward and reverse reactions is summed up by Newton's first law of thermodynamics