# What is the mass of one mole of (NH_2)_3PO_4?

Of $\text{ammonium phosphate, } 149.09 \cdot g \cdot m o {l}^{-} 1$
The salt you have written would not be isolable from water. $\text{Ammonium phosphate}$ is ${\left(N {H}_{4}\right)}_{3} P {O}_{4}$
$\text{Ammonium biphosphate } {\left(N {H}_{4}\right)}_{2} H P {O}_{4}$ is commonly used as an agricultural fertilizer.