0.001 mol of CrNH35NO3SO4 was passed through a cation exchanger and the acid coming out of it required 20 mL of 0.1 M NaOH for neutralisation. Hence, the complex is

Meq of acid = Meq sof Base = 20 x 0. I = 2 Compound is CrNH35SO4(0.001 mole ) For A: CrNH35SO4NO3→ it violate Werner's theory. Also meg of acid obtained =1×1≠2⇒(A) is wrong.  For B: Acid obtained is H2SO4:Meqacid =1×2=2Also it does not violate Werner's theory and hence Answer is B.For C: It violates Werner's theory CN of Cr is 6.