Electrochemistry Flashcards
Electrochemical reactions are spontaneous reactions that
Produce electrical energy and nonspontaneous reactions that use electrical energy to produce chemical change
What do electrochemical reactions involve?
The transfer electrons via redox reactions
Electrochemical cells contain systems in which
Redox reactions occur
What are two types of Electrochemical cells?
- Galvanic / Voltaic
- Electrolytic cells
Galvanic / Voltaic cells have what kind of reactions?
Spontaneous
Electrolytic cells have what kind of reactions?
Nonspontaneous
Where do redox reactions occur in electrochemical cells?
In electrodes, which act as electrical conductors
What are the two electrodes found?
- Anodes
- Cathodes
Anodes are electrodes in which
Oxidation occurs
Cathodes are electrodes in which
Reduction occurs
How is ∆G in Galvanic Cells?
-∆G, making them spontaneous
How is the Ecell of Galvanic Cells?
+ Ecell
How are Galvanic Cells?
They supply energy that is harnessed by placing redox half-rxns in half cells connected by apparatus
What is the purpose of the apparatus in Galvanic Cells?
It allows for the flow of electrons between half-cells, creating a circuit
How do electrons flow?
From the anode to the cathode
What is the purpose of the salt bridge in Galvanic Cells?
Prevents charge buildup
How do salt bridges prevent charge buildup in Galvanic Cells?
They contain inert electrolytes
How is ∆G in Electrolytic Cells?
+∆G, making them nonspontaneous
How is the Ecell of Galvanic Cells?
- Ecell
Electrophoresis is a technique used to separate
AAs based on isoelectric pts
In electrophoresis, cations navigate towards the
Cathode
In electrophoresis, anions navigate towards the
Anode
Quantitative electrochemistry explains the
Number of moles exchanged within a balanced reaction
What is the charge of an electron?
1.6E-19
1 mol of an electron has the change of?
1 F, or 10E5
What is the equation used to determine the number of electrons transferred?
i • t = n • F
The reduction potential determines which species is
Oxidized or reduced
The more positive the reduction potential is the
Greater the reduction
Reduction potential is measured in
Volts
What is the Standard Reduction Potential (Eº)?
The Standard Reduction Potential (Eº) measured under standard conditions
The higher the Eº is, the
Greater the tendency for reduction
The lower the Eº is, the
Greater the tendency for oxidation
What is the emf of a cell?
It is the difference in potential between 2 half-cells
What is the equation of emf/Eºcell?
Eºcell = Eºred + Eºoxid
What are the equations of Gibbs Free Energy?
∆G = -nFEcell ∆G = -RTlnKeq
What is the Nernst Equation?
Ecell = Eºcell - (RT/nF)(lnQ)
