A voltaic cell is constructed with two -Zn electrodes,where the half-reaction is + → Zn (s)E° = -0.763 V The concentrations of zinc ion in the two compartments are 4.50 M and 1.11 × M,respectively.The cell emf is ________ V.

Question

A voltaic cell is constructed with two  -Zn electrodes,where the half-reaction is  +  → Zn (s)E° = -0.763 V The concentrations of zinc ion in the two compartments are 4.50 M and 1.11 ×  M,respectively.The cell emf is ________ V.

Quizplus · Accepted Answer

To calculate the cell potential, we need to use the Nernst equation:

Ecell = E°cell - (RT/nF) * ln(Q)

where:
E°cell = standard cell potential
R = gas constant (8.314 J/mol*K)
T = temperature in Kelvin
n = number of electrons transferred in the cell reaction
F = Faraday constant (96485 C/mol)
Q = reaction quotient

First, let's calculate Q:

Q = ([Zn2+] cathode/[Zn2+] anode)^n
n = 2 (from the balanced half-reaction)

Q = (1.11*10^-3/4.50)^2
Q = 6.43*10^-7

Next, we need to calculate the cell potential:

Ecell = -0.763V - (0.0257V/2) * ln(6.43*10^-7)
Ecell = 0.0772V

Therefore, the answer is choice C, 0.0772.

A Voltaic Cell Is Constructed with Two -Zn Electrodes,where