posted by Chum .
Calculate the molecular mass of the nonionic solutes: 64.3 g of solute in 390 g of water raises the boiling point to 100.680 degrees C.
Isn't your subject chemistry?
boiling point eleveation= Kb*molality
.680=molessolute/kgwater * .52
solve for molessolute, then molessolute=massingrams/molemass and you can solve for massingrams.