## Entropy

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

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Imani Johnson 1H
Posts: 14
Joined: Sat Jul 23, 2016 3:00 am

### Entropy

Explain this to me conceptually,

how can you determine the sign of entropy when just given a reaction and no numbers? For example, the midterm gives the rxn: CO2(g)+H2O(l)-->H2CO3(aq).

How do you go about this?

Mimi Lec 2H
Posts: 29
Joined: Fri Jul 22, 2016 3:00 am

### Re: Entropy

Solids have lower molar entropy than liquids, and liquids have lower molar entropy of gases. In the gas phase, a compound has the highest molar entropy. I think there will be a decrease in entropy for this equation, because of the conversion of a gas and a liquid which have high molar entropy, into an aqueous solution.

Chem_Mod
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### Re: Entropy

Also, when the number of molecules decreases, translational and rotational degrees of freedom are converted to vibrational degrees of freedom, which contribute less to entropy, and therefore entropy decreases.

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