Which of the following statement is not valid for oxoaids of phosphorus?

Options

A. Orthophosphoric acid is used in the manufacture of triple superphosphate
B. Hyprophosphorous acid is a diprotic acid
C. All Oxoacids contain tetrahedral four cordinated phosphorous
D. All oxoacids contain at least one `P=O` unit and one `P-OH` group.

Answer

2

Explanation

Hypophophorous acid (phosphinic acid )is monoprotic as only one `H` aotm is directly bonded to oxygen:

the fertility of soil can be enhanced by using chemical fertilisers which provide the central plant nutrients : K-N and `P`. The most important phosphate fertiliser is the Fuperphosphate of lime, `Ca(H_(2)PO_(4))_(2)`. This is produced directly form phosphate rocks by the treatemt with concentrated sulphuric acid. In the way ,insoluble phosphate rock is rendered souble in water to improve the release of phosphorous to the soil for uptake by the plants,
`Ca_(3)(PO_(4))_(2)+2H_(2)SO_(4)rarrCa(H_(2)PO_(4))_(2)+2CaSO_(4)`
Phosphatic rock generally contains fluoride which reacts with `H_(2)SO_(4)` to give hydrogen fluoride which in turn generates other side products the gases side products are removed by washing witbh water in a scrubber ,Almost `90%` of the phosphate rock mined goes into the production of phosphatic fertilisers, the remiaining `10%` is used for the production of elemental phosphrous .Treatment of phosphate rock with phosphoric acid yields triple super -phosphate `Ca(H_(2)PO_(4))_(2)`. `2H_(2)O` which a free form calcium sulphate and hence contains a greater percentage of phosphorus:
`Ca_(5)(PO_(4))_(3)F+7H_(3)PO_(4)+5H_(2)O rarr 5Ca(H_(2)PO_(4))_(2).H_(2)O+HF`