Unit 9: Thermochemistry

What do state functions depend on and what are some examples?

They depend on the final and initial values, not the path taken. Examples include Pressure, Volume, Temperature, Energy, and Enthalpy.

What do path functions depend on and what are some examples?

They depend on the path taken. Examples include work and heat.

What is an exothermic reaction?

Released heat out of the system into the surroundings (Heat as a product-)

What is an endothermic reaction?

Heat is released from the surroundings into the system (Heat as a reactant +)

How do states of matter relate to entropy (S)?

Gas>Solution>Liquid>Solid (measure of disorder)

What in entropy is favorable or unfavorable?

Endothermic reactions are unfavorable and positive entropy is favorable.

Values of Gibbs and their meaning?

G<0 spontaneous in the forward direction

G>0 spontaneous in the reverse direction

G=0 equilibrium

H and S: Spontaneous at all temperatures?

H is negative and S is positive

H and S: Spontaneous in the reverse direction?

H is positive and S is negative

H and S: Spontaneous at low temperatures

Both are negative (enthalpy driven)

H and S: Spontaneous at high temperatures

Both are positive (entropy driven)