Q. 48

When a metal of group 1 was dissolved in liquid ammonia, the following observations were obtained:

(i) Blue solution was obtained initially.

(ii) On concentrating the solution, blue colour changed to bronze colour.

How do you account for the blue colour of the solution? Give the name of the product formed on keeping the solution for some time.

Answer :

Alkali metals dissolve in liquid ammonia to give a deep blue colour. These solutions are also conducting in nature. The blue colour is obtained because of ammoniated electron which absorbs energy in the visible region of light and thus imparts blue colour to the solution. The reaction is given as

M + (x+y)NH3 [M(NH3)x]+ + [e(NH3)y]-


As the concentration of the metal increases, the colour of the solution become bronze in colour, which is due to the formation of metal ion clusters.


If the product formed is kept standing for some time, it slowly liberates hydrogen resulting in the formation of amide.


M+(am) + e- +NH3(l) MNH2(am) +1/2H2(g)


Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Interactive quiz on s-Block ElementsInteractive quiz on s-Block ElementsInteractive quiz on s-Block Elements34 mins
Test your knowledge on S-Block ElementsTest your knowledge on S-Block ElementsTest your knowledge on S-Block Elements43 mins
Fall in Love with INORGANIC : Important Compounds of Sodium - S block CemistryFall in Love with INORGANIC : Important Compounds of Sodium - S block CemistryFall in Love with INORGANIC : Important Compounds of Sodium - S block Cemistry53 mins
Fall in Love with INORGANIC: Important Compounds of Calcium - S block CemistryFall in Love with INORGANIC: Important Compounds of Calcium - S block CemistryFall in Love with INORGANIC: Important Compounds of Calcium - S block Cemistry45 mins
Interactive Quiz | p Block elements | Check YourselfInteractive Quiz | p Block elements | Check YourselfInteractive Quiz | p Block elements | Check Yourself43 mins
Oxides of Nitrogen and Phosphorus FamilyOxides of Nitrogen and Phosphorus FamilyOxides of Nitrogen and Phosphorus Family41 mins
d-block Contractiond-block Contractiond-block Contraction61 mins
Understand R and S NomenclatureUnderstand R and S NomenclatureUnderstand R and S Nomenclature60 mins
Lecture on Electronic Configuration of ElementsLecture on Electronic Configuration of ElementsLecture on Electronic Configuration of Elements64 mins
Practise Questions on R and S nomenclaturePractise Questions on R and S nomenclaturePractise Questions on R and S nomenclature55 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
caricature
view all courses