A chromium complex with a formula CrCl _ 3 6 H _ 2 O has a spin only magnetic moment value of 3.87 BM and its solution conductivity corresponds to 1: 2 electrolyte. 2.75 g of the complex solution was initially passed through a cation exchanger. The solution obtained after the process was reacted with excess of AgNO _ 3 . The amount of AgCl formed in the above process is \_\_\_\_ g. (Nearest integer) [Given: Molar mass in g mol ^ -1 Cr : 52 ; Cl : 35.5, Ag : 108, O : 16, H : 1]
A. A
The complex CrCl _3 6 H _2 O with magnetic moment 3.87 BM indicates 3.87 = n(n+2) giving n = 3 unpaired electrons, confirming Cr³⁺. A 1:2 electrolyte means structure is [ Cr(H _2 O )_5 Cl ]^ 2+ Cl _2^-. Molar mass = 52 + 5(18) + 35.5 + 6(18) = 285.5 g/mol. Moles of complex = 2.75/285.5 = 0.00963 mol. After cation exchange, 2 Cl⁻ remain per formula unit (from the 1:2 electrolyte), giving 0.00963 × 2 = 0.01926 mol of free Cl⁻. Reacting with excess AgNO₃: mass of AgCl = 0.01926 × 143.5 = 2.76 g ≈ 3 g (nearest integer).
Related: Chemistry — Coordination Compounds · All PYQ Banks