A solution containing 1.2 g nonvolatile solute in 100 g. of a solvent has a boiling point elevation 1.2 K. Calculate the molar mass of solute if molal elevation constant of solvent is 6.5 K kg mol ⁻¹ .

Step-by-step solution

The elevation in boiling point is given by the formula: T_b = K_b m where m is the molality of the solution, which can be written as: m = w₂ 1000 M₂ w₁ Substituting the given values w₂ = 1.2 g , w₁ = 100 g , T_b = 1.2 K , and K_b = 6.5 K kg mol ⁻¹ : 1.2 = 6.5 1.2 1000 M₂ 100 1.2 = 6.5 12 M₂ M₂ = 6.5 12 1.2 M₂ = 65 g mol ⁻¹ Answer: 65 g mol ⁻¹