All alkali metals dissolve in anhydrous liquid ammonia to give a blue colour solution. It is the ammoniated electron which is responsible for the blue colour of the solution, and the electrical conductivity is due to ammoniated cation, {[M{(N{H_3})_x}]^ + } as well as the ammoniated electron, {[e{(N{H_3})_y}]^ - }, values of x and y depends on the extent of solvation by N{H_3} ​. Dilute solutions are paramagnetic due to free ammoniated electrons.What happens if alkali metals are allowed to react with concentrated liquid ammonia?(A) Paramagnetic character of solvated electrons is retained(B) Solvated electrons associate to form electron pairs and paramagnetic character decreases(C) Reducing character is increased(D) Reducing character is not affected

When alkali metals react with concentrated liquid ammonia, the solvation of electrons by ammonia molecules is more extensive compared to dilute solutions. Here's how each option relates to this scenario:

Option (A): Paramagnetic character of solvated electrons is retained:

This option suggests that the paramagnetic nature of solvated electrons remains unchanged. However, in concentrated liquid ammonia, solvated electrons can associate to form pairs due to stronger solvation effects.
Option (B): Solvated electrons associate to form electron pairs and paramagnetic character decreases:

This is a plausible outcome. In concentrated liquid ammonia, the strong solvation can lead to the pairing of solvated electrons, thereby reducing their paramagnetic character.
Option (C): Reducing character is increased:

Concentrated liquid ammonia can indeed increase the reducing character of the system. The solvated electrons are highly reactive and can facilitate stronger reducing properties.
Option (D): Reducing character is not affected:

This is less likely because concentrated liquid ammonia enhances the reducing properties due to the presence of highly solvated electrons.
Considering these points, the most appropriate answer to the question "What happens if alkali metals are allowed to react with concentrated liquid ammonia?" would likely be option (C): Reducing character is increased. This is because concentrated liquid ammonia provides a more conducive environment for the formation of solvated electrons, which are highly reducing species.