1) MX2 dissociates into M2+ and X- ions in an aqueous solution, with a degree of dissociation ( α) of 0.5. The ratio of the observed depression of freezing point of the aqueous solution to the value of the depression of freezing point in the absence of ionic dissociation is A) 4 B) 3 C) 1 D) 2 Answer: Option DExplanation:MX2→M2++2X− van't Hoff factor for any salt can be calculated using equation i=1+α(n−1) where ,n= number of constituent ions ∴ i(MX2)=1+α(3−1) =1+2α (△Tf)observed(△Tf)teoretical=i=1+2α ∴ i=1+2 x0.5 i=2