[au5467]

Okay, this was the referance that I was looking at.

"Test for the presence of phosphate ion, PO₄^3-. Add 1ml of 6M HNO₃ to 1ml of 0.5M Na₂HPO₄. Then add 1ml of 0.5M (NH₄)₂MoO₄ and stir thoroughly. A precipitate forms, (NH₄)₃PO₄•12MoO₃, which indicates the presence of phosphate." -Experiment 35: Spot Tests for Some Common Ions

I set up the equation,
2HNO₃ + Na₂HPO₄ --> 2NaNO₃ + H₃PO₄

and set this up...this is the equation that I'm struggling with:
H₃PO₄ + (NH₄)₂MoO₄ --> (NH₄)₃PO₄• 12MoO₃

the first equation that I "solved" can be wrong, so please tell me if there is error.

I'm soo confused right now...   how do you balance the last equation? Or how do you get the net ionic equation from this question? I've spent many, many hours and I still can't figure it out.

[AWK]

H3PO4 + 12(NH4)2MoO4 + 21HNO3 = (NH4)3PMo12O40 21NH4NO3 + 12H2O

[Hello12]

http://www.webqc.org/balance.php