Calculate molality of the solution containing nonvolatile solute if boiling point elevation of the solution is 0.2 ~K [ ~K _ b =0.52 ~K ~kg ~mol ⁻¹ ]

Step-by-step solution

The boiling point elevation T_b = K_b m relates to molality m through the ebullioscopic constant K_b = 0.52 K kg mol⁻¹ . Given T_b = 0.2 K , solving for molality yields m = T_b K_b = 0.2 0.52 = 0.385 mol kg⁻¹ to three significant figures. This value corresponds to option C among the given choices.