[eprigge]

I have about a pound of silver nitrite that I'd like to oxidize into the nitrate.  The nitrite is somewhat soluble at 4.2g/L, so that's good news.  I'm thinking that hydrogen peroxide would work although it may decompose in the presence of silver ions first.  Would simple exposure to oxygen work?  Any ideas?

Thanks!

[curiouscat]

I'd try the H2O2. Just be careful of any quick decomposition.

[cooltix4ACID]

I'm not really sure, but what I would recommend or try myself is that exposure to oxygen in the air would probably work, but would take a pretty long time.
So what I would do is, if you want faster processes is use first 3% hydrogen peroxide, but it would take time too.
For, some really fast processes I would think is use above 30% concentrations of hydrogen peroxide, and see what happens, or you could try higher concentrations of 95% Nitric Acid could be used as a Strong oxidising agent.

2NO2-(aq) + O2(g) = 2NO3-(aq)

NO2-(aq) + H2O2(aq) = NO3-(aq) + H2O

NO2-(aq) + H+(aq) + NO3-(aq) = NO3-(aq) + H2O(l) + NO2(g)[Very Toxic]


AGAIN!!!, just recommending, this is what I would try first.

[AWK]

First of all silver nitrate(III) is more expensive than silver nitrate(V).
The simplest way to proceed this (if this is absolutely needed) is just replacing reaction with HNO₃. Oxidation with HNO₃ is of course possible but mainly you got replacing instead of oxidation using solid AgNO₂ instead of its solution. Using  replacing reaction can give concentrated solution of silver nitrate in a few minutes.

[Wastrel]

Silver in various forms is really good at catalysing decomposition of hydrogen peroxide.  I'd avoid this.

Nitric acid + fume hood sounds good to me.