Question

Give reasons:

Cr²⁺ is a strong reducing agent whereas Mn²⁺ is not (Cr = 24, Mn = 25).

Answer 1

1. Cr²⁺ has the electronic configuration 3d⁴ and tends to lose one electron to reach the more stable 3d³ (Cr³⁺), making it easily oxidized and thus a strong reducing agent.
2. Mn²⁺ has the configuration 3d⁵, which is a half-filled stable configuration; losing an electron is less favorable, so it is less reducing.
3. Cr²⁺ tends to get oxidized to Cr³⁺, a more stable state, releasing electrons easily.
4. Mn²⁺ is more stable and less likely to lose electrons, so it is not a strong reducing agent.