Why are phase changes endothermic?

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Michelle Wang 4I
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Joined: Fri Sep 28, 2018 12:27 am

Why are phase changes endothermic?

Postby Michelle Wang 4I » Sun Jan 27, 2019 3:03 pm

Why are phase changes from solid-->liquid-->vapor endothermic reactions?

705170809
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Re: Why are phase changes endothermic?

Postby 705170809 » Sun Jan 27, 2019 3:14 pm

Phase changes are endothermic because heat is required to break the bonds between the atoms in order for it to go from a solid to a liquid or a liquid to a gas. This is why during a phase change, the temperature does not change.

varunhariharan
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Re: Why are phase changes endothermic?

Postby varunhariharan » Sun Jan 27, 2019 3:37 pm

These phase changes all require bonds to be broken which require an input of energy.

Jonathan Pai 2I
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Re: Why are phase changes endothermic?

Postby Jonathan Pai 2I » Sun Jan 27, 2019 3:43 pm

Think of how we looked at endothermic reactions in equilibrium and boiling water. If you boil water (add heat), what happens. Water vapor is formed (product), so the added heat from the stove created more products, which is the characteristic of an endothermic reaction.

H2O(l) + heat <> H2O(g) , shifts right when heat added

eden tefera 2B
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Re: Why are phase changes endothermic?

Postby eden tefera 2B » Sun Jan 27, 2019 3:48 pm

Phase changes like freezing, however release energy into the surroundings so it can be considered exothermic.

Lisa Werner 2F
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Re: Why are phase changes endothermic?

Postby Lisa Werner 2F » Sun Jan 27, 2019 4:10 pm

Phase changes involving the breaking of bonds (solid->liquid->gas) are endothermic because they require/absorb heat. Phase changes involving the formation of bonds (gas->liquid->solid) are exothermic because the release heat.

chris_tsai_4H
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Joined: Fri Sep 28, 2018 12:26 am

Re: Why are phase changes endothermic?

Postby chris_tsai_4H » Sun Jan 27, 2019 4:15 pm

Phase changes are endothermic because, in order to go from one state of matter to another, the bonds have to be broken, which requires heat.

Mhun-Jeong Isaac Lee 1B
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Re: Why are phase changes endothermic?

Postby Mhun-Jeong Isaac Lee 1B » Sun Jan 27, 2019 4:43 pm

Phase change from solid to liquid to gas requires energy in order for the bonds to be broken. Therefore, they are endothermic.

davidryan3f
Posts: 63
Joined: Fri Sep 28, 2018 12:23 am

Re: Why are phase changes endothermic?

Postby davidryan3f » Sun Jan 27, 2019 4:57 pm

Phase changes from solid-->liquid-->vapor are endothermic reactions because it requires an input of heat and energy to break the intermolecular forces.

Esther Lee 4H
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Joined: Fri Sep 28, 2018 12:29 am

Re: Why are phase changes endothermic?

Postby Esther Lee 4H » Sun Jan 27, 2019 5:42 pm

when you break the forces youre inputting heat so its considered an endothermic reaction

704913468
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Re: Why are phase changes endothermic?

Postby 704913468 » Sun Jan 27, 2019 8:33 pm

Phase changes are endothermic because of the heat released from bonds breaking.

704913468
Posts: 17
Joined: Wed Nov 15, 2017 3:02 am

Re: Why are phase changes endothermic?

Postby 704913468 » Sun Jan 27, 2019 8:34 pm

Phase changes are endothermic because of the heat released from bonds breaking.


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