MHT CET202617 April 2026Morning ShiftChemistrySolutionsActual
Calculate the molar mass of nonvolatile solute when 4 g of it is dissolved in 100 g solvent that boils at 319.4 K [ K_b = 2.4 K kg mol ⁻¹ ; B.P of pure solvent = 319 K]
Options
- A220 gmol ⁻¹
- B230 gmol ⁻¹
- C240 gmol ⁻¹
- D250 gmol ⁻¹
Correct answer
C. 240 gmol ⁻¹
Step-by-step solution
Elevation in boiling point is given by T_b = T_b - T_b^0 T_b = 319.4 - 319 = 0.4 K Using the formula for elevation in boiling point: T_b = K_b m = K_b w₂ 1000 M₂ w₁ Substituting the given values: 0.4 = 2.4 4 1000 M₂ 100 0.4 = 96 M₂ M₂ = 96 0.4 = 240 g mol ⁻¹ Answer: 240 gmol ⁻¹