# What is the oxidation number for each atom? (NH4)2Ce(SO4)3.

## All numbers are supposed to subscripts.

Jul 21, 2017

Subscripts?.......We commonly superscript the oxidation number.

#### Explanation:

We have the $C e \left(I V\right)$ salt, ${\left(N {H}_{4}^{+}\right)}_{2} {\left[C e {\left(S {O}_{4}\right)}_{3}\right]}^{2 -}$, $\text{ceric ammonium sulfate}$

Now the sum of the oxidation numbers equals the charge on the ion. For $N {H}_{4}^{+}$ we gots $4 \times \stackrel{+ I}{H}$, and $1 \times \stackrel{- I I I}{N}$; the sum of the oxidation numbers is $+ 1$ as required for the ammonium ion.

And for the ceric salt, we gots $\stackrel{+ I V}{\text{Ce}}$, and $\stackrel{V {I}^{+}}{S}$ and $\stackrel{- I I}{O}$: $4 + 3 \times 6 - 24 = - 2$ as required for ${\left[C e {\left(S {O}_{4}\right)}_{3}\right]}^{2 -}$

See here for general rules.