An alkaline earth metal.. (M) dissolves in liquid ammonia forming a deep blue-black solution. The reaction involved is . (A) M+2NH3 --- M(NH2)2 + 2NH2 (B) M +2xNH3 --- [M(NH3)x ] (C) M + 2NH4OH ---M(OH)2 + 2NH2 (D) M + (x+2y)NH3 ---- [M(NH3)x ] ^2+ + 2[e(NH3)y]- (e respect to electron)
Answers
HERE IS YOUR ANSWER,
⇔ The answer to your question is :
→ Ammoniated electrons absorb energy in the visible region of light so the solution is blue in colour.
→ Alkali metals namely Lithium, Sodium, Potassium, Rubidium, Cesium and Francium dissolve in liquid ammonia and give deep blue solutions. These solutions conduct electricity. They contain ammoniated cations and ammoniated electrons.
⇔ Reason :
⇒ M + (x+y) NH3 → M⁺(NH3)x + e⁻ (NH3)y Ammoniated cation Ammoniated Anion
⇔ THUS,
→ When ordinary light falls on this solution then electrons absorb this energy and gets excited to higher levels corresponding to red region of visible light.
→ As a result transmitted light is blue which imparts blue colour.
THEREFORE,
The correction option is D).
HOPE IT HELPS YOU,
THANK YOU. ^_^
The alkali metals like Na,K etc. dissolved in liquid Ammonia giving deep blue coloured solution.This solution is highly conducting in nature.It contains a large amount of Ammoniated captions as well as electrons as shown below in the reaction:-M + ( a + b )NH3 => M* ( NH3 )a + e(NH3)bIt has been found that the blue colour of solution is mainly due to the presence of the Ammoniated electrons in the solution.These electrons absorb energy corresponding to the red region of the visible light spectrum for its excitation to the higher energy levels.The transmitted light is blue coloured, thus it imparts blue colour to the solution.The solution is paramagnetic due to the presence and in the absence of catalysts and impurities decomposes the blue coloured solution and it gives formation to "Metal amide" and liberation of hydrogen gas.