Metal ammonia solution of grp 1 and grp 2 differ in?
Answers
When we add Group-1 and Group-2 metals to liquid ammonia, they dissolve to form metal cations and solvated electrons.
M+NH3(liq)⟶M++e−
Now, when the G-1 solutions evaporate, we get the metal back, but in the case of G-2 solutions (except Beryllium), they give a metal complex, [M(NH3)6].
"Evaporation of the ammonia from solutions of Group 1 metals yields the metal, but with Group 2 metals evaporation of ammonia gives hexammoniates [M(NH3)6] of the metals. These slowly decompose to give amides."
Page No. 335, Chapter 11-'Group 2 - the alkaline earth elements', Concise Inorganic Chemistry
and,
"The alkaline earth metals except beryllium form similar solutions [to alkali metals] readily, but upon evaporation, a solid 'ammoniate', [M(NH3)x] is formed."
Page No. 249, Chapter 9-'Chemistry in Aqueous and Nonaqueous Solvents', Inorganic Chemistry: Principles of Structure and Reactivity
What is the reason for this contrasting behaviour, and do all Group 2 metals(except beryllium) exhibit such a property?
Source: