Which is the intramolecular oxidation-reduction reaction?

Options

A. `2KClO_(3) rarr 2KCl+3O_(2)`
B. `(NH_(4))_(2)Cr_(2)O_(7) rarr N_(2)+CrO_(3)+4H_(2)O`
C. `PCl_(5) rarr PCl_(3)+Cl_(2)`
D. All of the above

Answer

D

Explanation

(`a`) `underset(+1)underset(darr)(K)underset(+5)underset(darr)(Cl)underset(-2)underset(darr)(O_(3)), rarr underset(+1)underset(darr)(K)underset(-1)underset(darr)(Cl)+underset(0)(3O_(2))`
`Cl` is reduced and `O` is oxidised.
(`b`) `underset(-3)underset(uarr)((NH_(4))_(2))underset(+6)underset(uarr)(Cr_(2)O_(7)) rarr underset(0)underset(uarr)(N_(2))+underset(+3)underset(uarr)(Cr_(2)O_(3))`
`N` is oxidised and `Cr` is reduced
(`c`) `underset(+5)underset(uarr)(P)underset(-1)underset(uarr)(Cl_(5)) rarr underset(+3)underset(uarr)(P Cl_(3))+underset(0)underset(uarr)(Cl_(2))`
`P` is reduced and `Cl` is oxidised.