phase changes

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Ghadir Seder 1G
Posts: 134
Joined: Sat Sep 14, 2019 12:17 am

phase changes

Postby Ghadir Seder 1G » Sun Jan 26, 2020 1:09 pm

What are all the phase changes? Are they exothermic?

SarahCoufal_1k
Posts: 102
Joined: Thu Jul 25, 2019 12:17 am

Re: phase changes

Postby SarahCoufal_1k » Sun Jan 26, 2020 1:12 pm

I believe there are 6 phase changes.
3 are endothermic: Melting (solid to liquid) vaporization (liquid to gas) sublimation (solid to gas)
3 are exothermic: freezing(liquid to solid), condensation(gas to liquid) and deposition (gas to solid)

Jessica Li 4F
Posts: 115
Joined: Fri Aug 09, 2019 12:16 am

Re: phase changes

Postby Jessica Li 4F » Sun Jan 26, 2020 3:58 pm

A phase change occurs any time you convert a substance, between the three states of matter/phases: solid, liquid, and gas. There is also a fourth stage but it should be irrelevant to the class. You can determine which changes are exothermic and endothermic by comparing the relative energies of the different phases: gases have the highest energy, liquids are in the middle, and solids are the lowest.

Anokhi Patel 2B
Posts: 76
Joined: Fri Aug 09, 2019 12:17 am

Re: phase changes

Postby Anokhi Patel 2B » Sun Jan 26, 2020 4:02 pm

The phase changes that are endothermic are vaporization( liquid to vapor), fusion (solid to liquid) which is also known as melting, and sublimation (solid to vapor) like dry ice. The reverse reactions of these phase changes will be exothermic.

Andres Merlos 2L
Posts: 46
Joined: Wed Sep 18, 2019 12:17 am

Re: phase changes

Postby Andres Merlos 2L » Sun Jan 26, 2020 4:41 pm

The exothermic phase changes we are currently discussing are condensation, freezing, and deposition. The endothermic phase changes are vaporization, melting, and sublimation.

kevinolvera1j
Posts: 103
Joined: Fri Aug 02, 2019 12:15 am

Re: phase changes

Postby kevinolvera1j » Sun Jan 26, 2020 4:45 pm

since phase changes can be either exothermic or endothermic, they should be taken into account when calculating changes in enthalpy.

Kavya Immadisetty 2B
Posts: 106
Joined: Sat Aug 24, 2019 12:17 am
Been upvoted: 1 time

Re: phase changes

Postby Kavya Immadisetty 2B » Sun Jan 26, 2020 4:52 pm

not all phase changes are exothermic, some are endothermic


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