winter 2011 midterm, question 2B

[Erin Natale 3I]

Can anyone explain why Container A has the highest entropy? Why would a monatomic gas have a higher entropy than a vibrationally active diatomic gas?


Thanks!

[Alli Foreman 2H]

Each of the containers has the same number of moles of atoms. Since container A is a monoatomic gas, it has 1 mole of atoms running around and hitting each other. Container B is made up of diatomic molecules. This means that there are the same number of total atoms (1 mol), but since they are bound together diatomically (in groups of two) then there is only 0.5 mole of molecules running around and hitting each other. Entropy is essentially chaos, so the more particles there are running around and hitting each other, the larger your entropy value.