Chapter 17 Flashcards
spontaneous process
occur without ongoing outside intervention
when ice melts, water evaporates, or salt dissolves in water
the arrangement of molecules or ions becomes more disorderly.
second law
for any spontaneous process, the entropy of the universe increases (ΔSuniv > 0)
“Entropy of the universe is increasing.”
Know that the entropy of matter increases as it changes state from
solid to liquid to gas
Any spontaneous process is _____
irreversible!
thermodynamics predicts
whether a process will proceed under given conditions
entropy
a thermodynamic function that increases as the number of energetically equivalent ways of arranging the components increases.
positional entropy (why do gases expand in a vacuum?)
A gas expands into a vacuum because the expanded state has the highest positional probability of states available to the system.
Entropies of complex molecules are less than or greater than those of simple molecules.
greater
Entropy change is favorable when…
in a more random system
Entropies of solutions are greater than or less than those of pure liquids and solids.
greater
The Third Law of Thermodynamics
for a perfect crystal at absolute zero, the absolute entropy = 0 J/mol K.
Gibbs free energy
is the maximum amount of work energy that can be released to the surroundings by a system
first law
Energy is conserved.
standard entropy depends on…
the number of “places” to put that energy, including the state of the substance, the molar mass, the particular allotrope, the molecular complexity, and the extent of dissolution.
