Question

"When an alkali metal dissolves in liquid ammonia, the solution acquires different colours."
Answer whether the above statement is true or false.
If true enter 1, else enter 0.

Answer 1

When an alkali metal dissolves in liquid ammonia, the solution acquires different colours.

The alkali metals dissolve in liquid ammonia, the solubility may be as high as $5M$. The solutions are coloured and metastable. The dilute solutions are blue but colour changes to bronze with increasing concentration. The blue colour is attributed to the presence of solvated electrons, the reaction may be represented as :

$M+(x+y)N{H}_3⟶\left[M\right(N{H}_3{)}_x{]}^{+}+\left[e\right(N{H}_3{)}_y{]}^{-}$

In concentrated solutions, the ammoniated metal ions are bound by free unpaired electrons which give bronze colour. The blue solutions are paramagnetic, whereas the bronze – coloured solutions are diamagnetic.