When entropy=0 [ENDORSED]

[James_Duffek_2B]

Is it possible for a system to have no entropy? What would such a system look like?

[becky a 3D]

a system is said to have 0 entropy when there is only 1 microstate molecules can be in, meaning all molecules are in the same energy level. The equation S= k lnW shows that entropy equals 0 when w (which represents the total # of microstates for molecules) is equal to one, that is because ln(1)=0 . A system that has 0 entropy is found in diatomic molecules where the total number of possible positions is only 1 (e.g. O2) and at low temperatures (0 K) where there is no thermal disorder.

[danae_blodgett_1H]

What type of question would be asked in the case that entropy is equal to zero?

[Molika Soben_3J]

In the textbook, question 21 of chapter nine asks you to calculate the entropy of a solid nanostructure made of 64 molecules in which the molecules are aligned in the same direction. Since it is only arranged in one way, W would be 1^64 which would equal 1 and plug it into the equation for entropy and you will get 0 for the value of entropy compared to if the molecules lie in 4 directions which in that case W would be 4^64. Entropy will be equal to 0 if a system can only be prepared or arranged in one way.