What is the molality of NaCl in a 500 ml 20% aqueous NaCl solution whose density is 1.148 g/mL at 25C?

1 Answer
Feb 16, 2018

Well, we want....#"molality"="moles of solute"/"kilograms of solvent"#..I make it approx...#4*mol*kg^-1#

Explanation:

And we work from a #1*mL# volume of solution....the which has a mass of #1.148*g#...

And we gots #20%w/w......#

And so we gots...#((20%xx1.148*g)/(58.44*g*mol^-1))/(80%xx1.148*gxx10^-3*kg*g^-1)=??*mol*kg^-1#