Question

The metallic sodium disolves in liquid amonia to form a deep blue coloured solution. The deep blue colour is due to formation of.

• A. solvated electron, $\left[\text{e}\right(N{H}_3{)}_y{]}^{-}$
• B. solvated atomic sodium, $Na(N{H}_3{)}_y$
• C. $(N{a}^{+}+N{a}^{-})$
• D. $NaN{H}_2+H_2$

Answer 1

The correct option is A solvated electron, $\left[\text{e}\right(N{H}_3{)}_y{]}^{-}$

The alkali metals dissolve in liquid ammonia without evolution of hydrogen. The metal loses electrons and combine with ammonia molecule.
$M\to M^{+}\text{(in liquid ammonia)}+e^{-}\text{(ammoniated)}$
$M+(x+y)N{H}_3\to \left[M\right(N{H}_3{)}_x{]}^{+}{e}^{-}(N{H}_3{)}_y$
It is ammoniated electron which is responsible for colour.