All the alkali and alkaline earth metals dissolved in liquid ammonia, but few of them yields the metal on evaporation of ammonia from solution. Find the total number of such metals.
Na, K , Mg, Sr, Ca , Rb , Cs

Question

All the alkali and alkaline earth metals dissolved in liquid ammonia, but few of them yields the metal on evaporation of ammonia from solution. Find the total number of such metals.

Na, K , Mg, Sr, Ca , Rb , Cs

TestHub · Accepted Answer

Alkali metals (Na, K, Rb, Cs) yield the free metal back upon the evaporation of liquid ammonia. Alkaline earth metals (Mg, Ca, Sr) instead form stable metal-ammoniate complexes, such as $[M (N H_{3})_{6}]$ , rather than returning to their pure metallic state. In the provided list, only the four alkali metals—Na, K, Rb, and Cs—will yield the metal on evaporation.

Therefore, the total count of such metals is 4.

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