In: Chemistry
Constant | Value |
Ecu | 0.337 |
Ezn | -7.63 |
R | 8.314 |
F | 96,485 |
T | 298 |
In the activity, click on the E∘cell and Keq quantities to observe how they are related. Use this relation to calculate Keq for the following redox reaction that occurs in an electrochemical cell having two electrodes: a cathode and an anode. The two half-reactions that occur in the cell are
Cu2+(aq)+2e−→Cu(s) and Zn(s)→Zn2+(aq)+2e−
The net reaction is
Cu2+(aq)+Zn(s)→Cu(s)+Zn2+(aq)
Use the given standard reduction potentials in your calculation as appropriate.
Cu+2 + 2e- ===> Cu +0.337 V
Zn+2 + 2e- ===> Zn -0.763 V
E0 CelI = E0 (cathode) – E0(anode)
=+0.337 V – ( - 0.763V) = 1.10V
E0 = RT/nF*(lnQ)
R = 8.314 J⋅mol−1⋅K−1
F= 96,485 C/mol
T = 298 K
Q=K; putting values for each standard above equation can be written as
E0 cell = 0.0592/n log K
Where n is the number of electrons transferred, in this case n = 2
log K = n * E0 cell/0.0592
= (2) (1.10)/0.0592
= 37.126
Keq = antilog (37.162)
= 10^(37.162)
= 1.45 x 10^37