spontaneity

if a chemical reaction has a positive ΔH and a negative ΔS then…

nonspontaneous at all temperatures

if a chemical reaction has a negative ΔH and a positive ΔS then…

spontaneous at all T

if a chemical reaction has a positive ΔH and a postitive ΔS then…

spontaneous at high temp

nonspontaneous at low temp

if a chemical reaction has a negative ΔH and a negative ΔS then…

spontaneous at low temp

nonspontaneous at high temp

how do you find the total entropy of the universe (ΔSuniverse)

ΔS(universe) = ΔS(system) + ΔS (surrounding)

at equilibrium ΔS=? therefore ΔS(system)=?

ΔS=0

ΔS(system)=-ΔS(surrounding)

for a process at constant T and P, ΔG°=?

ΔG°= ΔH°-TΔS°

a process is pontaneous if: (ΔS(uni) and ΔG(sys) is…)

ΔS(universe) is positive

ΔG(System) is negative

for a reaction at constant T and P when ΔG(system) < 0 then…

spontaneous process

for a reaction at constant T and P when ΔG(system) > 0 then…

non-spontaneous process

for a reaction at constant T and P when ΔG(system) = 0 then…

equilibrium

equation to find crossover temperature

T=ΔH/ΔS

(since ΔG = 0 we set 0=ΔH-TΔS)

for lnK=(-ΔH/R)(1/T)+(ΔS°/R) what is slope and what is y-intercept when graphing lnK vs. 1/T

slope: (-ΔH/R)

y-tinercept: (ΔS°/R)