ch. 18

If the Gibbs free energy change of a reaction is positive, then the entropy of the universe is increasing and the reaction is considered spontaneous. True or False

False

Which of the following ideas about Gibbs free energy is false? DG = DH - TDS If DG for a process is positive, it is considered spontaneous. DG can indicate if a process is spontaneous by its sign. DGsystem = - TDSuniverse

If DG for a process is positive, it is considered spontaneous.

The Second Law of Thermodynamics states In spontaneous changes, the entropy of the universe increases. In chemical and physical changes, all energy is conserved. Energy is always released in spontaneous changes. In spontaneous changes, the entropy of the system increases.

In spontaneous changes, the entropy of the universe increases.

Which of the following does NOT result in an increase in entropy? Increase in temperature. Change from liquid to gas. Reaction that result in fewer gas molecules. Dilution.

Reaction that result in fewer gas molecules.

Which change listed below does NOT result in a decrease in entropy? The formation reaction of CaCO3. The precipitation of solid BaSO4. Vinegar freezing in the refrigerator. The combustion of octane, C8H18.

The combustion of octane, C8H18.

Some chemical reactions will only be spontaneous at lower temperatures. True or False

True

Spontaneous changes are favored by an increase in molecular disorder and a release of energy. True or False

True

The Third Law of Thermodynamics states that the entropy of a pure, perfect, crystalline solid at absolute zero is exactly zero. True or False

True