Gibbs Free Energy and Spontaneity

This video tutorial covers Gibbs free energy, focusing on the differences between standard and non-standard Delta G. It explains how to determine spontaneity and equilibrium, and provides practice calculations. The tutorial also discusses how temperature affects spontaneity, using examples to illustrate these concepts.

What does the non-standard Gibbs free energy determine about a reaction?

• The rate of a reaction

• The temperature of a reaction

• The spontaneity of a reaction

• Whether a reaction is at equilibrium

Which of the following conditions must be met to calculate standard Gibbs free energy?

• Pressure must be 1 atm

• Temperature must be 298 Kelvin

• Enthalpy must be non-standard

• Entropy must be non-standard

In the given examples, which condition makes a calculation non-standard?

• Standard enthalpy and entropy

• Non-standard temperature

• Standard temperature

• Non-standard pressure

What is the predicted sign of enthalpy for a combination reaction?

• Positive

• Negative

• Undefined

• Zero

Why is the formation of rust considered exothermic?

• It absorbs heat

• It releases heat

• It requires energy input

• It is temperature independent

What is the significance of a negative Delta G value?

• The reaction is non-spontaneous

• The reaction is endothermic

• The reaction is at equilibrium

• The reaction is spontaneous

At what temperature is the reaction spontaneous according to the practice calculation?

• At 788 Kelvin

• Below 788 Kelvin

• Above 788 Kelvin

• At 298 Kelvin

What happens to the spontaneity of a reaction when both enthalpy and entropy are negative?

• It becomes non-spontaneous at high temperatures

• It becomes non-spontaneous at low temperatures

• It becomes spontaneous at high temperatures

• It becomes spontaneous at low temperatures

What is the calculated temperature at which the reaction changes spontaneity?

• 2,997 Kelvin

• 1,000 Kelvin

• 500 Kelvin

• 3,500 Kelvin

Why is it practically impossible to carry out the reaction above 2,997 Kelvin?

• Solid iron and oxygen would not exist

• The reaction becomes endothermic

• The reaction reaches equilibrium

• The reaction rate becomes too slow