## Entropy at 0 Kelvin

Volume: $\Delta S = nR\ln \frac{V_{2}}{V_{1}}$
Temperature: $\Delta S = nC\ln \frac{T_{2}}{T_{1}}$

Jeremy_Guiman2E
Posts: 82
Joined: Fri Sep 28, 2018 12:29 am

### Entropy at 0 Kelvin

Why do molecules at 0 K have entropy still? Are there circumstances under which molecules could have no entropy?

Deepika Reddy 1A
Posts: 125
Joined: Thu Jul 11, 2019 12:15 am

### Re: Entropy at 0 Kelvin

I believe they explained this in the pizza rolls review session. They said that even if molecules are at 0 Kelvin, they still have positional entropy. In order to have no entropy, the molecule at 0 K has to be perfectly ordered.

Frank He 4G
Posts: 50
Joined: Tue Nov 12, 2019 12:19 am

### Re: Entropy at 0 Kelvin

One would need a perfect pure crystal of a molecule or atom at 0 K to have 0 entropy. If it is not, then there are possible chances for molecules or atoms existing in different positions.

KarineKim2L
Posts: 100
Joined: Fri Aug 30, 2019 12:16 am

### Re: Entropy at 0 Kelvin

Even at 0K, most molecules still have a degeneracy and therefore have residual entropy. If there is more than one way a molecule could be oriented or positioned, there will still be entropy at 0K.