UNIT 8

Question 1

entropy of the universe can only….

Answer 1

go up, it cannot go down

Question 2

ΔS_universe = ΔS_surr + ΔS > = 0

Answer 2

ΔS_uni increases for any irreversible process therefore can never be negative

ΔS_uni = 0 if all processes are reversible

Question 3

a system is spontaneous if its

Answer 3

irreversible aka above 0

Question 4

entropy increases when…

Answer 4

temp inc
volume inc
number of species inc
complexity of products inc
phase shift up ( solid to liquid to gas)

Question 4

ΔS°=

Answer 4

Σ vSm° (products) - Σ vSm° (reactants)
Sm° = standard molar entropy
v= stoich coefficient

Question 5

ΔG°=

Answer 5

Σ vΔGp° (products) - Σ vΔGr°(reactants)

also equal to:

ΔH° - TΔS°

Question 5

ΔS_surroundings =

Answer 5

-ΔH/T

Question 6

gibbs energy is spontaneous when

Answer 6

ΔG < 0

Question 6

gibbs energy is non spontaneous when

Answer 6

ΔG > 0

Question 7

is ΔH is negative (exothermic) and ΔS is positive than ΔG is

Answer 7

spontaneous

Question 8

if ΔH is positive (endothermic) and ΔS is negative then ΔG is

Answer 8

non spontaneous

Question 9

if ΔH is negative and ΔS is negative

Answer 9

it is spontaneous at low T and non-spontaneous at high T

Question 10

if ΔH is positive and ΔS is positive

Answer 10

it is non -spontaneous at low temps and spontaneous at high temps