Unit 9: Applications of Thermodynamics Flashcards
When does entropy increase
as matter becomes more dispersed
as temperature increases
What equation is used to calculate entropy
∑∆S˚products- ∑∆S˚reactants
When are processes considered thermodynamically favorable in relation to ∆G˚
when ∆G˚<0
When are processes considered thermodynamically unfavorable in relation to ∆G˚
when ∆G˚>0
What equations can be used to determine ∆G˚
∆H˚-T∆S˚
-RT lnK
-nFE˚
When will ∆G˚ be favorable in relation to ∆H˚, ∆S˚, and T
∆H˚<0, ∆S˚>0, at all T
∆H˚>0, ∆S˚<0, no temperatures
∆H˚>0, ∆S˚>0, high temperatures
∆H˚<0, ∆S˚<0, low temperatures
What is the indication behind a reaction that is at thermodynamically favorable temperatures but does not occur or occurs at an extremely slow rate
it has a high activation energy
What is favored in relation to K when ∆G˚<0
products (K>1)
What is favored in relation to K when ∆G˚>0
reactants (K<1)
What are external forces that can drive thermodynamically unfavorable reactions
electrical energy in electrolytic cells and batteries
light in photosynthesis
What is the flow of an electrochemical cell
- Start at the anode (electrons are lost here)
- Electrons travel through the wire and to the load (on fire)
- Electrons enter the cathode and reduce the cation
- The anions flow through salt bridge back to the anode
How do you calculate the standard cell potential of an electrochemical cell
sum of the two reduction half-reactions standard reduction potential
When are cells thermodynamically favorable in relation to E˚ and 0
E˚>0
When are cells thermodynamically unfavorable in relation to E˚ and 0
E˚<0
