Question

The elements of 3d transition series are given as:

Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn 

Answer the following:

Which element is a strong reducing agent in +2 oxidation state and why?

Answer 1

Cr, because Cr²⁺, which has [Ar] 3d⁴s⁰ configuration, tends to lose one more electron forming Cr³⁺ to attain the more stable half-filled tg(d³) configuration. This is proved by its negative reduction potential value.