Two aqueous solutions are prepared. Solution A contains 10.8 g of glucose in 200 mL of solution. Solution B contains 3.0 g of a weak monoprotic acid (HX) in 250 mL of solution. If both solutions boil at the same temperature, the percentage degree of dissociation of the weak acid HX is : [Given : Molar mass of glucose = 180 g mol ⁻¹ , Molar mass of HX = 60 g mol ⁻¹ ]

Step-by-step solution

For solutions to have the same boiling point, their effective molarities must be equal: i_A M_A = i_B M_B For Solution A (glucose, a non-electrolyte, i_A = 1 ): M_A = 10.8 180 1000 200 = 0.06 5 = 0.3 M For Solution B (weak acid HX): M_B = 3.0 60 1000 250 = 0.05 4 = 0.2 M Equating the effective molarities: 1 0.3 = i_B 0.2 i_B = 1.5 For a weak monoprotic acid, the van 't Hoff factor is i = 1 + , where is the degree of dissociation. 1 + = 1.5 = 0.5 Percentage degree of dissociation = 0.5 100 = 50 % . Answer: 50 %