Spontaneity, Entropy and Thermodynamics

The first law of thermodynamics states that :

• A process occurring at constant temp and pressure is spontaneous in the direction in which free energy decreases.

• Entropy of a perfect crystal at 0 K is zero.

• For any spontaneous process there is always an increase in the entropy of the universe.

• Energy in the universe is constant.

The second law of thermodynamics states that :

• A process occurring at constant temp and pressure is spontaneous in the direction in which free energy decreases.

• Entropy of a perfect crystal at 0 K is zero.

• For any spontaneous process there is always an increase in the entropy of the universe.

• Energy in the universe is constant.

The third law of thermodynamics states that :

• A process occurring at constant temp and pressure is spontaneous in the direction in which free energy decreases.

• Entropy of a perfect crystal at 0 K is zero.

• For any spontaneous process there is always an increase in the entropy of the universe.

• Energy in the universe is constant.

Free energy is a state function.

• True

• False

A process i said to be spontaneous if

• It is exothermic

• It occurs without outside intervention

• Entropy is decreased

• Products favor the reactants

Which 2 answers best describe entropy

• a measure of molecular randomness or disorder

• natural tendency towards order

• decreases in a spontaneous reaction

• denoted by the symbol S

Free energy is represented by the letter

• F

• E

• G

• S

If a reaction has a      - $\Delta$  H  then it is

• endothermic

• exothermic

If a reaction has a     + $\Delta$  H  then it is

• endothermic

• exothermic

Which would have the highest positional entropy?

• Solid CO₂

• Liquid CO₂

• Gaseous CO₂