T-3 Entropy Flashcards
State the 2nd law of thermodynamics
All spontaneous processes occur in a direction that increases the entropy of the universe
delta Suniverse =
Ssys + Ssurr
delta Suniverse ( >, <, = ) 0
delta Suniverse > 0
Ssys + Ssurr ( >, <, = ) 0
Ssys + Ssurr > 0
In a spontaneous process, what has to happen to delta Ssys if delta Ssurr is negative?
delta Ssys must be positive and larger than delta Ssurr so that delta Suniverse is greater than 0
Can a process be spontaneous if delta Ssys and Ssurr are both negative?
no because delta Suniverse would be less than 0
Can a process be spontaneous if delta Ssys and Ssurr are both positive?
yes, because delta Suniverse would have to be greater than 0
What are the units for entropy?
J/(mol•K)
Does increasing the temperature of a sample yield a positive or negative change in entropy?
positive
Does increasing the size of a container for a sample of gas yield a positive or negative change in entropy?
positive
Does increasing the number of particles in a container for a sample of gas yield a positive or negative change in entropy?
positive
Is condensing a liquid out of a gas a positive or negative change in entropy?
negative
Is melting a solid a positive or negative change in entropy?
positive
Which has a higher entropy, CH4 or H3CCH3?
H3CCH3, it has more atoms and a higher molar mass
Is compressing a gas in a syringe a positive or negative change in entropy?
Negative
