Which from following solutions exhibits minimum boiling point elevation under identical conditions? (Assume complete dissociation)

Step-by-step solution

The boiling point elevation T_b is given by T_b = i K_b m , where i is the van't Hoff factor and m is the molality. Since K_b is constant for the solvent, T_b is proportional to i m . For 0.05 m MgCl ₂ , which dissociates into three ions ( i = 3 ), the product is i m = 3 0.05 = 0.15 . Comparing with the other solutions: 0.2 m KCl gives 2 0.2 = 0.4 , 0.1 m NaCl gives 2 0.1 = 0.2 , and 1 m AlCl ₃ gives 4 1 = 4.0 . The minimum i m value is 0.15 , corresponding to 0.05 m MgCl ₂ . The solution exhibiting the minimum boi