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

Feb 23, 2017

Approx. $1.2 \cdot g$ of $\text{DAP}$...

#### Explanation:

$\text{Diammonium phosphate}$ is the stable material (called $\text{DAP}$). This is the material that is used as agricultural fertilizer:

${H}_{3} P {O}_{4} + 2 N {H}_{3} \rightarrow {\left(N {H}_{4}\right)}_{2} H P {O}_{4}$

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

$\text{Moles of phosphoric acid} = \frac{3.49 \cdot g}{98.08 \cdot g \cdot m o {l}^{-} 1} = 0.0356 \cdot m o l$

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

$0.0356 \cdot m o l \times 2 \times 17.03 \cdot g \cdot m o {l}^{-} 1 \equiv 1.21 \cdot g$

Note the assumptions in this answer. I would consider an answer based on ${\left(N {H}_{4}\right)}_{3} P {O}_{4}$ to be unreasonable. You will have to see your teacher's treatment.