An aqueous solution of ethanol is 14.1M C2H5OH. The density of the solution is 0.853g/mL. What is molality of ethanol in the solution? What is mass % of ethanol in solution?

Question

I got the molality which is -21.7 ethanol, but I can't figure out how to get the mass % from the molality?

Answer 1

molality = mols EtOH/kg solvent
Convert mols EtOH to grams. g = mols x molar mass.
Add g EtOH to 1000 for mass solution.
Then mass % = (grams EtOH/total grams)*100 = ?
By the way, I wonder how you obtained -21.7m. A negative number for concentration? I don't think so.