Question

(k) Discuss a method of estimation of phosphorus in an
organic compound.

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Answer 1

Answer:

Explanation:

A known mass of an organic compound is heated with fuming nitric acid where phosphorus present in the compound is oxidized to phosphoric acid. It is precipitated as ammonium phosphomolybdate, (NH4)3PO4.12MoO3, by adding ammonia and ammonium molybdate.

Alternatively, phosphoric acid may be precipitated as MgNH4PO4 by adding magnesia mixture which on ignition yields Mg2P2O7.

Let the mass of organic compound taken = m g

Mass of ammonium phospho molydate = m1 g

Molar mass of (NH4)3PO4.12MoO3 = 1877 g

Percentage of phosphorus = (31 x m1 x 100)/(1877 x m)