Answer to Question #142818 in Inorganic Chemistry for Shelby

Question

Given the orbital configuration of arsenic (As), explain how arsenic can have the following oxidation states.
+3 (for example, in AsCl3)
+5 (for example, in AsCl5)

Answer 1

Electronic configuration for Arsenic is -- [Ar] 3d10 4s2 4p3

As is group 15 element which all have general electronic configuration ns2 np3 in common giving 5 electrons in its valence electron shell. All elements of this group have common oxidation state of +3, +5 and -3 because they can form covalent bonds by sharing 3 or 5 electrons to becaome stable or in few cases, gain 3 or 5 electrons to complete their p suborbital or their whole shell respectively.

However, Arsenic has more stable and therefore more recognizable +3, -3 oxidation state than other group 15 elements due to "inert pair effect" of 3d orbital.