What is the oxidation state of S in $\mathrm{SO}_4^{2-}$ ?
What is the oxidation state of S in $\mathrm{SO}_4^{2-}$ ?
+6
-6
+2
+3
Solution
Let the oxidation state of S in $\mathrm{SO}_4^{2-}=x$
$\begin{array}{ll}
& x+4(-2)=-2 \\
\therefore \quad & x-8=-2 \\
\therefore \quad & x=8-2=+6
\end{array}$