Question

Alkali metals impart blue color to :
A.Acidic Solution
B.Ammonia Solution
C.Nitrate Solution
D.None of these

Answer 1

In the given question firstly we have to get the condition for both the reactions that are performed in the question and when we will get that we just have to apply the conditions in order to get the reaction and then we can get the correct answer for the given problem. Like for the reaction with the ammonical $AgN{O_3}$ , the reaction would be $C{H_3}{(C{H_2})_2}C \equiv CH \to white{\text{ }}precipitate$ .

Complete step by step answer:
Here according to the question statement we get that the question is basically on the chemical nature of the alkali metals.
Alkali metals are the basic group $1$ of the modern periodic table and they are quite reactive ones too when compared with the other metals of the table.
Here we have to solve the given question in the step by step analysis:
Step 1: We have to provide the basic chemical equation where the conversion of the metal atom into ammoniated metal ion ( ${M^ + }(N{H_3})$ ) is mentioned. Further it is mentioned the electron set free combines with $N{H_3}$ molecule in order to produce the characteristic ammonia solvated electron. This in case is blue in colour.
Step 2: The equation we need is the :
$Na + (x + y)N{H_3} \to {[Na{(N{H_3})_x}]^ + } + {[e(N{H_3})y]^ - }$
It is the equation showcasing the generation of the ammoniated cation and anions in the reactant part of the reaction.
Here there is also the generation of the ammoniated electron which would indeed be the main responsible for the visible blue colour.
It is also much paramagnetic in nature and thus the reducing power of alkali metals in ammonia solution is also showcased.
However, we can say that the imminent increased conductance nature of these metals in ammonia is also due to presence of ammoniated cation and ammonia solvated electrons.
So the right option would be option B, ammonia solution.

Note:
A solvated electron is a free electron in (solvated in) a solution, and is the smallest possible anion. Solvated electrons occur widely, although it is difficult to observe them directly because their lifetimes are so short.