Phosphorous acid on heating gives the following products:
`4H_(3)PO_(3)overset(Delta)rarr3H_(3)PO_(4)+PH_(3)` The above reaction is an example of

Options

A. oxidation
B. thermal decomposition
C. disproportionation
D. reduction

Answer

C

Explanation

`4H_(3)PO_(3)overset(Delta)rarr3H_(3)PO_(4)+PH_(3)`
In the reaction, the acid in+ 3 oxidation state of P tends to disproportionate to higher (+5) and lower (-3) oxidation state in `H_(3)PO_(4)` and `PH_(3)` respectively.