MHT CET202526 Apr 2025Evening ShiftChemistrySolutionsActual
Which of the following aqueous solutions having same molality exhibits maximum boiling point elevation? (Assume complete dissociation)
Options
- AKCl
- BNaCl
- CAlCl₃
- DBaCl₂
Correct answer
C. AlCl₃
Step-by-step solution
Boiling point elevation is a colligative property given by the formula T_b = i K_b m , where K_b and m are constant for all aqueous solutions. The elevation is therefore proportional to the van't Hoff factor i . For each solute: KCl dissociates as KCl K ^+ + Cl ^- , giving i = 2 . NaCl dissociates as NaCl Na ^+ + Cl ^- , giving i = 2 . AlCl₃ dissociates as AlCl₃ Al ³⁺ + 3 Cl ^- , giving i = 4 . BaCl₂ dissociates as BaCl₂ Ba ²⁺ + 2 Cl ^- , giving i = 3 . The highest van't Hoff factor is i = 4 for AlCl₃, which theref