Question

CoL63+ + e- <-----> CoL62+
The E nought for this redox system when L=H2O is 1.82 V and when L=NH3 is 0.11 V.
Comment on this.

Answer 1

col62 62?

Answer 2

L6 represents H2O and NH3.

Answer 3

(H2O)6 and (NH3)6

Answer 4

@chmvijay

Answer 5

okay, so if we have Co 3+ bonded to 6 ligands
and then on the right side we have Co2+ bonded to 6 ligands
the ligands change from H2O to NH3
so we have to examine the stability of the two compounds
Co(H2O)6 3+ vs Co(H2O)6 2+
and Co(NH3)6 3+ vs Co(NH3)6 2+
the redox potentials are telling us that the Co(H2O)6 2+ is much more stable than the Co(H2O)6 3+
now we have to determine that based on the ligands

Answer 6

hmm >.< I have found that the 3+ isn't as stable as the 2+, but I'm researching the low vs high spin - have you been doing that in class recently?
ligand field theory? O.o

Answer 7

separating out the d orbitals into low and high spins?
we have to determine which structure is more stable
Eo, voltage potential is just a measure of how stable the products are relative to the reactants so we can explain the different in stabilities in terms of the structure of the metal ligands

Answer 8

nope we have just learnt the basic ligand substitution reactions and redox potentials not field theory

Answer 9

So what's the problem.. we have to determine that based on the ligands. I think 3+ isn't as stable as the 2+
2+ is everywhere

Answer 10

Oh. This is a hard one. I have no ideas left... lol >.<

Answer 11

it says that he coablat present in the enviornment o fH2o want to be in the form of Co+2 and that of in ammonia enviornment want to be in the form of Co+3 according to the values ur given in Eo.

high crystal stablization energy for the Co(NH3)6 +3 compared to Co(NH3)+2

high crysta stablization energy for the CO(H2O)6+2 than the Co(H2O)+3
hence differnt in E0