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QUIZ one- question 1

Posted: Wed Feb 08, 2017 9:31 pm
by Stephanie_Martinez3E
Which molecule, when a single crystal, would you predict to have a larger molar entropy at T=0k; CO or N2? Why?

I know that CO has the larger molar entropy, but I don't understand why? If someone could help me, thanks!

Re: QUIZ one- question 1

Posted: Wed Feb 08, 2017 9:36 pm
by Chem_Mod
CO has more molecular arrangements since the two atoms are different.

Re: QUIZ one- question 1

Posted: Wed Feb 08, 2017 9:38 pm
by Chem_Mod
At T = 0 K there is no thermal energy to contribute to entropy in terms of molecular motion, rotation, vibration, etc.

However, several different configurations of the molecules in the crystal could be "frozen in" at T = 0 K depending on how many ways each could be oriented.

CO can be arranged in more distinct ways (more microstates) than N2 because of the asymmetry of CO across the bond vs. the symmetry N2.

C-O
or
O-C

vs.

N-N <-- only one way