[daylightsshadow]

Ok, so in a chem lab we did we synthesized Ni(diphos)Cl2, then we worked it up with NaOH and H2O2 before we titrated against AgNO3, now I have to answer the question "Why was the complex worked up with 30% H2O2/NaOH before the titrations?"

I am thinking that it has to do with oxidizing the Ni to Ni(II), but I am not sure and I think that there is something more than that.

[brudman]

You are correct to think that Nickel is being oxidized here, as H₂O₂ is a very strong oxidizing agent.
AgNO3 is being added to form an AgCl ppt in order to get rid of chlorines on the Ni complex.
I would assume that OH is replacing Cl on the nickel complex in this case, but I'm not too sure about it.
The hydroxy group is a much stronger binding ligand than chlorine so i think it is a pretty good assumption here.