NEETChemistryCoordination Compounds
A white precipitate X is insoluble in water but dissolves readily in aqueous ammonia to form a colourless, water-soluble complex Y . What are the chemical formulae of X and Y respectively?
Options
- AX = AgCl , Y = [ Ag ( NH ₃)₂]^+
- BX = AgBr , Y = [ Ag ( NH ₃)₂]^+
- CX = AgCl , Y = [ Ag ( NH ₃)₄]^+
- DX = PbCl ₂, Y = [ Pb ( NH ₃)₄]²⁺
Correct answer
A. X = AgCl , Y = [ Ag ( NH ₃)₂]^+
Step-by-step solution
Among the given halides, AgCl is a white precipitate, whereas AgBr is pale yellow. AgCl dissolves in aqueous ammonia due to the formation of the soluble diamminesilver(I) complex. The coordination number of Ag ^+ in this complex is 2. The reaction is: AgCl(s) + 2 NH ₃ (aq) [ Ag ( NH ₃)₂]^+ (aq) + Cl ^- (aq) Thus, X is AgCl and Y is [ Ag ( NH ₃)₂]^+ . PbCl ₂ does not dissolve in aqueous ammonia to form a coordination complex. Answer: X = AgCl , Y = [ Ag ( NH ₃)₂]^+