# Which element would be the most potent oxidizing agent out of scandium and iron, and out of manganese and chromium?

Oct 23, 2017

Well which element in each pair has the most valence electrons....?

#### Explanation:

So for scandium and iron, the choice is clear. and the highest oxidation state I know is $F e \left(V I +\right)$, which is expressed in (the rare) $F e {O}_{4}^{2 -}$. Scandium forms almost exclusively $S c \left(I I I +\right)$, complexes, mind you, there are a few novel subvalent $S {c}^{0}$, $S {c}^{+}$ or $S {c}^{2 +}$ species, and these are exceptionally rare.

For manganese and chromium, we got $M n \left(V I I +\right)$ in $M {n}_{2} {O}_{7}$.....I have never used this but it is apparently a volatile liquid; of course, it is a potent oxidant. $C r \left(V I +\right)$ is present in $C r {O}_{3}$ and $C r {O}_{4}^{2 -}$...all of these species are used as oxidizing agents....

Oct 26, 2017

The oxidation state of any element in its free state is zero, but $\text{Mn}$ and $\text{Fe}$ are tied for the highest observed oxidation states in their compounds.

#### Explanation:

Are you asking about the highest known oxidation state of these elements in their compounds?

Manganese

The electron configuration of $\text{Mn}$ is ${\text{[Ar] 4s"^2 "3d}}^{5}$.

The most common oxidation states of $\text{Mn}$ in its compounds, are +2, +3, +4, +6, and +7.

Since $\text{Mn}$ has seven valence electrons, +7 is its highest possible oxidation state, as in the purple permanganate ion, $\text{MnO"_4^"-}$.

Chromium

The electron configuration of $\text{Cr}$ is ${\text{[Ar] 4s 3d}}^{5}$.

The most common oxidation states of $\text{Cr}$ in its compounds, are are +2, +3, and +6.

Since $\text{Cr}$ has six valence electrons, +6 is its highest possible oxidation state, as in the yellow chromate ion, $\text{CrO"_4^"2-}$ and the orange dichromate ion, $\text{Cr"_2"O"_7^"2-}$.

Scandium

The electron configuration of $\text{Sc}$ is $\text{[Ar] 4s"^2 } 3 d$.

The most common oxidation state of $\text{Sc}$ in its compounds is +3.

Since it has three valence electrons, +3 is its highest possible oxidation state, as in scandium(III) chloride, ${\text{ScCl}}_{3}$.

Iron

The electron configuration of $\text{Fe}$ is ${\text{[Ar] 4s"^2 "3d}}^{6}$.

The most common oxidation states of $\text{Fe}$ in its compounds are +2 and +3.

Its highest oxidation state is +7, as in the extremely rare $\text{FeO"_4^"-}$ ion.

Chromium

The electron configuration of $\text{Cr}$ is ${\text{[Ar] 4s 3d}}^{5}$.

The most common oxidation states of $\text{Cr}$ in its compounds, are +2, +3, and +6.

Since it has six valence electrons, +6 is its highest oxidation state, as in the yellow chromate ion, $\text{CrO"_4^"2-}$ and the orange dichromate ion, $\text{Cr"_2"O"_7^"2-}$.