General Questions | JEE 2011 | Discussion Page

When a metal rod M is dipped into an aqueous colourless concentrated solution of compound N, the solution turns light blue. The addition of aqueous NaCl to the blue solution gives a white precipitate O. Addition of aqueous NH₃ dissolves O and gives an intense blue solution

The final solution contains

$[Pb(NH_{3})_{4}]^{2+}$ and

$[CoCl_{4}]^{2-}$

$[Al(NH_{3})_{4}]^{3+}$ and

$[cu(NH_{3})_{4}]^{2+}$

$[Ag(NH_{3})_{2}]^{+}$ and

$[Co(NH_{3})_{4}]^{2+}$

$[Ag(NH_{3})_{2}]^{+}$ and

$(Ni(NH_{3})_{6}]^{2+}$

Answer:

Option C

Explanation:

Since in the beginning, concentrated AgNO₃ solution was taken some AgNO₃ remain in solution gives precipitate of $AgCl$ on addition of NaCl. The precipitate finally dissolve in ammonia and Cu²⁺ present in solution forms complex with ammonia as

$Cu(NO_{3})_{2}+4NH_{3}(aq) \rightarrow [Cu(NH_{3})_{4}]^{2+}+2NO_{3}$

Blue

$AgCl(s)+2NH_{3}(aq) \rightarrow [Ag(NH_{3})_{2}]^{+}+Cl^{-}$

Discussion Forum

Answer:

Explanation: