Question

Addition of excess aqueous ammonia to a pink coloured aqueous solution of MCl₂.6H₂O(X) and NH₄Cl gives an octahedral complex Y in the presence of air. In aqueous solution, complex Y behaves as 1:3 electrolyte. The reaction of X with excess HCl at room temperature results in the formation of a blue coloured complex Z. The calculated spin only magnetic moment of X and Z is 3.87 B.M., whereas it is zero for complex Y. Among the following options, which statement(s) is(are) correct? 

(A) Addition of silver nitrate to Y gives only two equivalents of silver chloride 

(B) The hybridization of the central metal ion in Y is d²sp³ 

(C) Z is a tetrahedral complex 

(D) When X and Z are in equilibrium at 0°C, the colour of the solution is pink

Answer 1

(B, C, D)

X and Z in equilibrium at 0°C => then equilibrium is shifted towards X, making colour of solution pink.