1.

In an organic compound phosphorus is estimated as

Answer»

`Mg_(2)P_(2)O_(7)`
`Mg_(3)(PO_(4))_(2)`
`H_(3)PO_(4)`
`P_(2)O_(5)`

Solution :A pre-weighed amount of organic compound is heated with concentrated nitric acid `(HNO_(3))` in a tube. Phosphorus present in the compound GETS converted into phosphoric acid. Now the content of tube are heated with magnesia mixture i.e. `MgSO_(4)+NH_(4)Cl +NH_(4)OH , ` so formed which is collected , washed , DRIED and ignited to get magnesium pyrophosphate `Mg_(2)P_(2)O_(7)`, which is the weighed.
`UNDERSET("acid")underset("Phosphoric")(H_(3)PO_(4)) overset("Magnesia mixture")to underset("phosphate (white ppt.)")underset("(Magnesium ammonium)")(MgNH_(4)PO_(4)+3HCl)`
`2MgNH_(4)PO_(4) overset(DELTA)toMg_(2)P_(2)O_(7) DARR + 2NH_(3) +H_(2)O`
Knowing the weight of `Mg_(2)P_(2)O_(7)` , percentage of phosphorus can be calculated.


Discussion

No Comment Found

Related InterviewSolutions