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

2 Answers
Oct 23, 2017

Answer:

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 #Fe(VI+)#, which is expressed in (the rare) #FeO_4^(2-)#. Scandium forms almost exclusively #Sc(III+)#, complexes, mind you, there are a few novel subvalent #Sc^0#, #Sc^(+)# or #Sc^(2+)# species, and these are exceptionally rare.

For manganese and chromium, we got #Mn(VII+)# in #Mn_2O_7#.....I have never used this but it is apparently a volatile liquid; of course, it is a potent oxidant. #Cr(VI+)# is present in #CrO_3# and #CrO_4^(2-)#...all of these species are used as oxidizing agents....

Oct 26, 2017

Answer:

The oxidation state of any element in its free state is zero, but #"Mn"# and #"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 #"Mn"# is #"[Ar] 4s"^2 "3d"^5#.

The most common oxidation states of #"Mn"# in its compounds, are +2, +3, +4, +6, and +7.

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

Chromium

The electron configuration of #"Cr"# is #"[Ar] 4s 3d"^5#.

The most common oxidation states of #"Cr"# in its compounds, are are +2, +3, and +6.

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

Scandium

The electron configuration of #"Sc"# is #"[Ar] 4s"^2 "3d#.

The most common oxidation state of #"Sc"# in its compounds is +3.

Since it has three valence electrons, +3 is its highest possible oxidation state, as in scandium(III) chloride, #"ScCl"_3#.

Iron

The electron configuration of #"Fe"# is #"[Ar] 4s"^2 "3d"^6#.

The most common oxidation states of #"Fe"# in its compounds are +2 and +3.

Its highest oxidation state is +7, as in the extremely rare #"FeO"_4^"-"# ion.

Chromium

The electron configuration of #"Cr"# is #"[Ar] 4s 3d"^5#.

The most common oxidation states of #"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, #"CrO"_4^"2-"# and the orange dichromate ion, #"Cr"_2"O"_7^"2-"#.