Electrochemistry

Review Packet

Objectives:

• Identify and compare the two types of electrochemical cells: galvanic and electrolytic
• Draw and label a galvanic cell, including labeling the electrodes, the flow of electrons, and the flow of ions
• Write the half-reactions and determine which reaction occurs at the anode and which occurs at the cathode
• Give the line notation for a galvanic cell or write a balanced redox reaction from the given line notation
• Calculate the cell potential for a galvanic cell and an electrolytic cell
• Determine if a reaction is spontaneous from its cell potential
• Calculate the cell potential under nonstandard conditions when the solutions are not 1M using the Nernst equation
• Determine the strengths of oxidizing agents and reducing agents
• Draw and label an electrolytic cell
• Determine the reactions which occur at the anode and the cathode during electrolysis
• Perform stoichiometric calculations involving electrolysis
• Faraday’s Laws
• The relationship between emf and Free energy

Chapters 4, 20

Equations (from yellow sheet)

I = q/t

ΔG° = - nFE° = - RT ln K_eq

ΔG = ΔG° + RT lnQ = ΔG° + 2.303 RT log Q

E_cell = E°_cell – ^RT/_nF lnQ = E°_cell – ^0.0592/_n log Q @ 25° C

Notes

I. Galvanic Cells

A. Components of the galvanic cell

B. Line notation

C. Standard reduction potentials

· Activity series in metals

D. Calculating the cell potential of a galvanic cell

E. Spontaneous reactions

F. Cell dependence on concentration

G. Determining the strength of oxidizing and reducing agents

II. Electrolytic Cells

A. Reactions that occur in electrolytic cell

B. Stoichiometry of electrolytic processes

C. Comparison of galvanic and electrolytic cells

III. Electrolysis

A. Nernst equation

B. Electrolysis

· Purification of metals by electrolysis

IV. Faraday’s Laws

A. Laws

B. Quantitative treatment of Faraday’s Laws