Exam 4 Flashcards
What is electroanalytical chemistry?
A group of analytical methods involving the measurement of the movement of electrons.
What are the two types of electrochemical cells?
- Galvanic
- Electrolytic
What is the function of the anode in an electrochemical cell?
Oxidation occurs here.
What is the function of the cathode in an electrochemical cell?
Reduction occurs here.
What is the role of a salt bridge in an electrochemical cell?
Permits the movement of charged species to maintain charge balance.
What is the difference between galvanic and electrolytic cells?
- Galvanic: Stores energy for use (e.g., batteries)
- Electrolytic: Powered by an external source (e.g., electroplating, hydrolysis)
In a galvanic cell, what happens when a high impedance meter is connected?
Does not permit flow of charge.
What occurs when a low impedance device is connected to a galvanic cell?
Electrons flow from the anode to the cathode.
What is the convention for communicating an Ecell?
Translate the ‘picture’ from right to left.
What do phase interfaces in Ecell notation signify?
Designated by a single vertical line.
What is the standard potential for a half-cell with P_H2 = 1.00 atm and [H+] = 1.00 mol/L?
0.000 V.
What does the cell potential measured against the Standard Hydrogen Electrode (SHE) indicate?
The cell potential of the half reaction as a reduction.
What determines if the cell potential varies?
If the concentrations or pressures are not 1.
What is the relationship between cell potential and Gibbs free energy change (ΔG)?
ΔG = -nFE_cell.
What are some concerns for Galvanic cells?
- Activity vs concentration
- Diffusion limited
- Competing or additional equilibria
- Kinetic issues
