MHT CET202519 Apr 2025Evening ShiftChemistrySolutionsActual
Calculate the molal elevation constant of solvent if boiling point of 0.12 m solution is 319.8 K (Boling point of solvent =319.5 ~K )
Options
- A2 0 ~K ~kg ~mol ⁻¹
- B3.0 ~K ~kg ~mol ⁻¹
- C2.5 ~K ~kg ~mol ⁻¹
- D3 5 ~K ~kg ~mol ⁻¹
Correct answer
C. 2.5 ~K ~kg ~mol ⁻¹
Step-by-step solution
The molal elevation constant K_b relates boiling point elevation to solute molality through the relation T_b = K_b m . The boiling point elevation is calculated from the difference between solution and solvent boiling points: 319.8 - 319.5 = 0.3 K . Solving for K_b and substituting the given molality m = 0.12 mol kg⁻¹ yields K_b = 0.3 0.12 = 2.5 K kg mol⁻¹ . Final answer: C