Question

What is the molality of a solution containing 19.5g HCl and 257g of H2O?

Answer 1

M= 2.06

molality is m = moles/kg

if you look at the periodic table the mass of HCl is 36.458 rounded to 36.5

divide the 19.5g by the mass (36.5) and you’ll get 0.53

next, you convert g to kg so you divide by 1,000. 257/1,000 = 0.257

you plug those two answers into the equation > m= 0.53 mol HCl/ 0.257kg H20

the answer will be 2.06 when you divide and there’s how you get the molality.

remember, HCl is the solute and H20 is the solvent.