What does the the release or absorption of energy indicate? a. physical change b. chemical change c. physical and chemical changes d. neither physical nor chemical changes

C.physical and chemical changes.

Spontaneity tell us the direction of the reaction, but not how fast it goes. gibbs free energy brings together enthalpy, entropy and temperature in one easy formula. g = h - ts. and, finally the sign of delta g is always negative for a spontaneous reaction.

The teacher is mostly talking about the distillation of a mixture