Oxidation number of $\mathrm{P}$ in $\mathrm{PO}_4^{3-}$, of $\mathrm{S}$ in $\mathrm{SO}_4^{2-}$ and that…
Oxidation number of $\mathrm{P}$ in $\mathrm{PO}_4^{3-}$, of $\mathrm{S}$ in $\mathrm{SO}_4^{2-}$ and that of $\mathrm{Cr}$ in $\mathrm{Cr}_2 \mathrm{O}_7^{2-}$ are respectively :
$+3,+6$ and +6
$+5,+6$ and +6
$+3,+6$ and +5
$+5,+3$ and +6
Solution
$\mathrm{PO}_4^{3-}$, oxidation no. of $\mathrm{P} \Rightarrow+5$ $\mathrm{SO}_4^{2-}$, oxidation no. of $\mathrm{S} \Rightarrow+6$ $\mathrm{Cr}_2 \mathrm{O}_7^{2-}$, oxidation no. of $\mathrm{Cr} \Rightarrow+6$