In: Chemistry
the voltage for the electrochemical cell shown below was .450 V.
Pt(s)|Cd(NO3)2 (aq)(.0100M) || Cl- (aq) | AgCl (s)| Ag(s)
The standard reduction potentials are
Cd2++2e---> Cd (s) Eo= -.402 V
AgCl+e---> Ag(s) + Cl- Eo=.222V
Calcuate the concentration of Cl- if the cell potential was determined to be 0.605 V
Cd(s) -------------------> Cd^2+ (aq) + 2e^- E0 = 0.402v
2AgCl(s) + 2e^- ----------> 2Ag(s) + 2Cl^- (aq) E0 = 0.222v
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Cd(s) + 2AgCl(s) --------------> Cd^2+ (aq) + 2Ag(s) + 2cl^- E0cell = 0.45v
n = 2
ECell = E0cell - 0.0592/n log[Cd^2+]Cl^-]^2
0.605 = 0.45 - 0.0592/2 log0.01[Cl^-]^2
0.605-0.45 = -0.0296log0.01[Cl^-]^2
0.155 = -0.0296log0.01[Cl^-]^2
log0.01[Cl^-]^2 = -0.155/0.0296
log0.01[Cl^-]^2 = -5.24
0.01[Cl^-]^2 = 10^-5.24
0.01[Cl^-]^2 = 5.75*10^-6
[Cl^-]^2 = 5.75*10^-6/0.01
[Cl^-]^2 = 5.75*10^-4
[Cl^-] = 2.4*10^-2 M >>>>answer