The freezing point of 58.43 g of a pure solvent is measured to be 49.23 ºc. when 2.75 g of an unknown solute (assume the van 't hoff factor = 1.) is added to the solvent the freezing point is measured to be 46.54 ºc. answer the following questions ( the freezing point depression constant of the pure solvent is 7.78 ºc·kg solvent/mol solute).