Entropy

exam 4, chem 116, WVU spring '26

ΔN (gas) > 0

increase in entropy (n)

More kinetic energy =

more entropy (k)

More particles =

more entropy (p)

Dissolution =

more entropy (d)

ΔS > 0

making a mixture

ΔS < 0

separating a mixture

R is in terms of

J/K (not KJ)

3rd Law of Thermodynamics

At 0° K, entropy of a pure substance is 0 J/K

2nd Law of Thermodynamics

entropy of the universe is always increasing

Direction of spontaneity is encouraged by

ΔH < 0 and ΔS > 0

Remember to convert all temperatures to

kelvin!!

S_f⁰: definition

entropy at standard conditions

ΔS_f⁰: formula

S_f⁰ (products) - S_f⁰ (reactants)

ΔS_surroundings =

-ΔH / T

ΔS_universe =

ΔS_system + ΔS_surroundings