Arrange the following equimolar solutions according to increasing order of osmotic pressure [Assume complete ionisation] A. KCl B. BaCl ₂ C. AlCl ₃ D. Al ₂ ( SO ₄ )₃

Step-by-step solution

Osmotic pressure ordering depends directly on the van't Hoff factor for equimolar electrolyte solutions at constant temperature. Recall that for ideal solutions, osmotic pressure = iCRT , with C molar concentration, R the gas constant, and T temperature. With C and T equal, i . For KCl: dissociation gives KCl K ^+ + Cl ^- i = 2 For BaCl ₂ : BaCl ₂ Ba ²⁺ + 2 Cl ^- i = 3 For AlCl ₃ : AlCl ₃ Al ³⁺ + 3 Cl ^- i = 4 For Al ₂( SO ₄)₃ : Al ₂( SO ₄)₃ 2 Al ³⁺ + 3 SO ₄²⁻ i = 5 Increasing i values: 2 Thus _ KCl