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Posted: Tue Feb 28, 2017 4:28 pm
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?
Posted: Tue Feb 28, 2017 4:33 pm
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.
Posted: Tue Feb 28, 2017 6:44 pm
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.