Calculate the number of moles of nonvolatile solute dissolved in 0.3 kg solvent if T _ b =0.3 ~K and K _ b for solvent is 1.8 ~K ~kg ~mol ⁻¹

Step-by-step solution

The boiling point elevation T_b = K_b m relates the ebullioscopic constant K_b to the molality m of a solution. Given T_b = 0.3 K and K_b = 1.8 K kg mol ⁻¹ for a solvent mass of 0.3 kg , the number of moles is determined by rearranging the molality expression: moles = T_b mass _ solv K_b = 0.3 0.3 1.8 = 0.09 1.8 = 0.05 Among the options, 0.05 is closest to 0.051 . Final answer: A