All Flashcards
What are the key differences between thermodynamically favorable and unfavorable reactions?
Favorable: ΔG° < 0, K > 1, spontaneous | Unfavorable: ΔG° > 0, K < 1, nonspontaneous.
What are the differences between voltaic and electrolytic cells?
Voltaic: Spontaneous redox reaction, produces electricity | Electrolytic: Nonspontaneous redox reaction, requires electricity.
Define 'thermodynamically favorable reaction'.
A reaction that occurs spontaneously, with ΔG° < 0 and K > 1.
Define 'thermodynamically unfavorable reaction'.
A reaction that does not occur spontaneously, with ΔG° > 0 and K < 1.
Define 'electrolytic cell'.
A cell that uses electrical energy to drive a nonspontaneous redox reaction.
Define 'coupled reactions'.
Reactions that involve a nonspontaneous reaction and a spontaneous reaction that share a common intermediate, allowing the nonspontaneous reaction to proceed.
Define 'common intermediate'.
A substance produced in one step of a reaction mechanism and consumed in a later step.
What is the effect of a positive ΔG° on a reaction's spontaneity?
The reaction is nonspontaneous and requires an external energy source to proceed.
What is the effect of coupling a nonspontaneous reaction with a highly spontaneous reaction?
If the spontaneous reaction's negative ΔG° is large enough, the overall coupled reaction becomes spontaneous.
What is the effect of multiplying a reaction by a coefficient on its ΔG° value?
The ΔG° value is multiplied by the same coefficient.
What is the effect of adding two reactions together?
The ΔG° values of the two reactions are also added together to find the ΔG° of the overall reaction.
What is the effect of using an external power source on a nonspontaneous reaction in an electrolytic cell?
The external power source provides the necessary energy to drive the nonspontaneous reaction forward.