Question

What mass of ammonium phosphate can prepared from a mass of `3.49*g` mass of phosphoric acid?

Answer 1

Approx. `1.2*g` of `"DAP"`...

Explanation:

`"Diammonium phosphate"` is the stable material (called `"DAP"`). This is the material that is used as agricultural fertilizer:

`H_3PO_4 + 2NH_3rarr(NH_4)_2HPO_4`

So following the given reaction, we assume that the phosphoric acid consumes a twice molar quantity of ammonia.

`"Moles of phosphoric acid"=(3.49*g)/(98.08*g*mol^-1)=0.0356*mol`

And mass of ammonia consumed is a TWICE molar quantity, given the stoichiometric equation:

`0.0356*molxx2xx17.03*g*mol^-1-=1.21*g`

Note the assumptions in this answer. I would consider an answer based on `(NH_4)_3PO_4` to be unreasonable. You will have to see your teacher's treatment.