A `0.141g` sample of phosphorus containing compound was digested in a mixture of `HNO_(3)` and `H_(2)SO_(4)` which resulant in formnation of `CO_(2), H_(2)O` and `H_(3)PO_(4)`. Addition of ammounium molybdate yielded a solid having the composition `(NH_(4))_(3) PO_(4).12MoO_(3)`. The precipitate was filtered, washed and dissolved in `50.0mL` of `0.20M NaOH`.
`(NH_(4))_(3) PIO_(4).12MoO_(3(s)) + 26OH^(-) rarr HPO_(4)^(2-) + 12MoO_(4)^(2-) + 14H_(2)O + 3NH_(3(g))`
After boiling the solution to remove the `NH_(3)`, the excess of `NaOH` was titrated with `14.1 mL` of `0.174M, HCl`. Calculate the percentage of phosprous in the sample.

Answer

`6.4%`