Question

The alkali metals dissolve in ammonia to give a deep blue solution which is conducting in nature.
$M+(x+y)N{H}_3\to \left[M\right(N{H}_3{)}_x{]}^{2+}+2\left[e\right(N{H}_3)y{]}^{-}$
Which of the following is not true about the solutions are alkali metals in liquid ammonia?

• A. The blue colour is due to ammoniated electron.
• B. The solution is paramagnetic.
• C. The blue colour changes to brown on standing.
• D. In concentrated solution blue colour changes to bronze and becomes diamagnetic.

Answer 1

The correct option is C The blue colour changes to brown on standing.

Alkali metals dissolve in ammonia to give a deep blue solution which is conducting in nature. It changes from blue to bronze as it changes from paramagnetic to diamagnetic.

$M+(x+y)N{H}_3\to \left[M\right(N{H}_3{)}_x{]}^2+2\left[e^{-}\right(N{H}_3\left)\right]$