Question

$AgCl\downarrow +2N{H}_3\rightleftharpoons \underset{soluble}{\left[Ag\right(N{H}_3{)}_2{]}^{+}}+C{l}^{-}$

Consider the above equilibrium

White ppt of AgCl appears an adding :

• A. ${NH}_3$
• B. $aq.NaCl$
• C. $aq.{HNO}_3$
• D. $aq.{NH}_{4}Cl$

Answer 1

The correct option is B $aq.NaCl$

When NaCl is added, it dissociates completely as it is a strong electrolyte.
This increases the concentration of chloride ions.
The equilibrium for the formation of silver ammonia complex shifts to left which decreases the chloride ion concentration and nullifies the increase in the concentration of chloride ions.
Hence, the precipitate of silver chloride appears.
When nitric acid is added, it combines with ammonia to form ammonium nitrate which decreases the concentration of ammonia.
Hence, the equilibrium for the formation of silver ammonia complex shifts to left and the precipitate of silver chloride appears.