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Computing cell potentials
Posted: Tue Apr 04, 2023 1:53 am
by Dhamnekar Winod
The standard reduction potential for the reaction\([Co(H_2O)_6]^3+(aq) + e^- \to [Co(H_2O)_6]^2+ (aq) \) is about 1.8 V. The standard reduction potential for the reaction\([Co(NH_3)_6]^3+(aq) + e^- \to [Co(NH_3)_6]^2+ (aq)\) is + 0.1 V.
Compute the cell potentials to show whether the complex ions, \([Co(H_2O)_6]^2+ \text{and/or} [Co(NH_3)_6]^2+,\)
can be oxidized to the corresponding cobalt(III) complex by oxygen.
Re: Computing cell potentials
Posted: Tue Apr 04, 2023 11:48 am
by ChenBeier
Need the redox potential of Oxygen and the Nernst equation.
Re: Computing cell potentials
Posted: Fri Jun 30, 2023 9:39 am
by penaltyshooters
To determine whether the complex ions [Co(H2O)6]2+ and/or [Co(NH3)6]2+ can be oxidized to the corresponding cobalt(III) complex by oxygen, we compare their reduction potentials with the reduction potential of oxygen. The reduction potential of oxygen is approximately 1.23 V.
For [Co(H2O)6]2+:
Cell potential = reduction potential of [Co(H2O)6]2+ - reduction potential of oxygen
Cell potential = 1.8 V - 1.23 V = 0.57 V
For [Co(NH3)6]2+:
Cell potential = reduction potential of [Co(NH3)6]2+ - reduction potential of oxygen
Cell potential = 0.1 V - 1.23 V = -1.13 V
Based on the cell potentials, only [Co(H2O)6]2+ can be oxidized to the corresponding cobalt(III) complex by oxygen, as its cell potential is positive. [Co(NH3)6]2+ cannot be oxidized by oxygen as its cell potential is negative.