Electrochemistry

Question 0

delta G^o =

Answer 0

-nFE^o_(cell)

Question 1

delta G =

Answer 1

-nFE_(cell)

Question 2

Relationship between delta G and delta G^o

Delta G =

Answer 2

Delta G^o + RTln(Q)

Question 3

Reaction Quotient

Q =

Answer 3

[products]^{(coefficient)} / [reactants]^{(coefficient)}

Question 4

Nernst Equation

E_(cell) =

Answer 4

E^o_(cell) - (RT/nF)ln(Q)

Question 5

Simplified Nernst Equation

E_(cell) =

Answer 5

E^o_(cell) - (0.0592/n)log(Q)

Question 6

At equilibrium:

Since E_(cell) = 0 and Q = K_(eq)

E^o_{<span>(ce</span>ll)} =

Answer 6

(0.0592/n)log(K_(eq))

Question 7

Concentration Cell:

Since E^o_(cell) = 0

E_(cell) =

Answer 7

0 - (0.0592/n)•log([M_anode]/[M_cathode])

Question 8

Electrochemical Cells

Answer 8

Systems that incorporate a redox reaction to produce or utilize electrical energy.

Question 9

Voltaic Cell

Answer 9

Uses a spontaneous reaction to generate electrical energy. The difference in free energy between higher energy reactants and lower energy products is converted into electrical energy. The system does work on the surroundings.

Question 10

Electrolytic Cell

Answer 10

Uses electrical energy to drive a nonspontaneous reaction. An external source supplies free energy to convert lower energy reactants into higher energy products. The surroundings do work on the system.

Question 11

Electrodes

Answer 11

Conduct the electricity between cell and surroundings.

Question 12

Electrolyte

Answer 12

A mixture of ions that are involved in the reaction or carry the charge.

Question 13

Which half reaction occurs at the anode?

Answer 13

Oxidation, electrons lost by the substance being oxidized leave the oxidation half-cell at the anode.

Question 14

Which half reaction occurs at the cathode?

Answer 14

Reduction, electrons gained by the substance being reduced enter the reduction half-cell at the cathode.

Question 15

Half-cell

Answer 15

Consists of one electrode dipping into an electrolyte solution in any voltaic cell.

Question 16

What are the charges of the anode and cathode in any voltaic cell?

Answer 16

The anode has a negative charge, and the cathode has a positive charge.

Question 17

Salt Bridge

Answer 17

Joins the half-cells and acts like a “liquid wire,” allowing ions to flow through both compartments and complete the circuit. Anions move right to left to the anode through the salt bridge. Cations move left to right to the cathode through the salt bridge.

Question 18

Active Vs. Inactive Electrodes

Answer 18

The active electrodes are themselves components of the half-reactions. Inactive electrodes are used when their are no reaction components that can be physically used as an electrode, and are used to transfer electrons.

Question 19

1 Volt =

Answer 19

1 Joule/Coulomb

Question 20

E^o_{(cell) =}

Answer 20

E^o_cathode - E^o_anode

or

E^o_reduction + E^o_oxidation

Question 21

Amp

Answer 21

1 Coulomb / Second