JEE Main 2025 Apr 7 Shift 1, Chemistry Q24: Abnormal Molar Masses

JEE Main2025Apr 7, Shift 1Chemistry

The percentage dissociation of a salt (MX $_{3}$ ) solution at given temperature (van't Hoff factor i = 2) is.................... % (Nearest integer)

Your answer

Solution

MX $_{3}$ dissociates completely into 4 ions: M $^{3 +}$ + 3X $^{-}$ . So $n = 4$ .

The van't Hoff factor for partial dissociation with degree $α$ :

$i = 1 + (n - 1) α$

Substitute $i = 2$ and $n = 4$ :

$2 = 1 + 3 α \Rightarrow α = \frac{1}{3} \approx 0.3333$

Percentage dissociation $= 33.33% \approx 33%$ .

$∴$ Answer = 33.

Concept behind this question

Concept-wise practice with instant solutions on Fundamenthol.