In ammonium−-phosphomolybdate, the oxidation state of MoMo is +_______

The oxidation state of Mo in ammonium phosphomolybdate can be determined by understanding the overall charge of the compound and the charges of the other elements present.

1. Ammonium phosphomolybdate has the formula (NH4)3[PMo12O40].

2. The ammonium ion (NH4+) has a charge of +1. Since there are three ammonium ions, the total positive charge is +3.

3. The phosphate ion (PO4) has a charge of -3.

4. The compound is neutral overall, so the total charge of the 12 Mo atoms must balance out the +3 from the ammonium ions and the -3 from the phosphate ion. This means the total charge of the 12 Mo atoms is 0.

5. Therefore, the oxidation state of each Mo atom is 0/12 = 0.

So, the oxidation state of Mo in ammonium phosphomolybdate is 0.