[formaldehyde23]

Here is a question that I'm having some trouble with; I proposed an explanation, but I'm not sure if it's right.

Which oxoanion, CrO₄(2-) or WO₄(2-) is expected to be the stronger oxidizing agent?

My explanation: We need to find the atom (Cr) or (W) that will most likely be reduced. CrO₄(2-) is the more unstable of the two molecules; this is because Cr has a smaller size than W. So, the oxygen atoms will repel each other.

I thought it would be easier to add an electron to a molecule that is already unstable.

Is this logic correct?

[mkurek]

What does an oxidizing agent do?

An oxidizing agent accepts electrons, thus the oxidizing agent is reduced.

Now lets take a look at our good old friend the periodic table, does the fact that chromium is exactly two rows above tungsten tell us anything? What kind of trends do we know about involving the periodic table that could help us out here?

[formaldehyde23]

So, if tungsten lies below chromium, it has a larger atomic radius. Does that mean that it's more willing to take another electron? (i.e. there's more room).

So, by this logic, is it true that WO₄^2- is a stronger oxidizing agent?