Alkali metals are good reducing agents why?

Why Sm^(2+) , Eu^(2+) and Yb^(2+) ions in solutions are good reducing agents but an aqueous solution of Ce^(4+) is a good oxidising agent?

Alkali metals are not found in free state why?

Ammonia is a good complexing agent. Why?

H_2S acts only as reducing agent while SO_2 acts as an oxidising as well as reducing agent. Why?

Whose metal dust is used as a reducing agent in dye industry?

Complete the following chemical reaction equations. P_4 + NaOH+H_2O rarr , I^-(aq)+H_2O(l)+O_3(g) rarr . H_2S acts only as reducing agent while SO_2 acts as an oxidising as well as reducing agent. Why?

BiH_3 is the strongest reducing reducing agent of group 15 elements. Why?