posted by lily on .
an aq. solution(NaCl) made by using 133g diluted to a total solution volume of 1 L.Calculate the molarity, molality & mass % of the solution(density of solution = 1.08g/mL)
[ans: M=1.92M, m=2.0m, 10.4 %]
i need the calculation work bcus my ans is contradict from the real ans.
I don't want to work the problem for you but here are the definitions. Actually, that's all you need with the data you have.
M = #moles/L soln
m = #moles/kg solvent
mass% = grams solute/100 g soln
You get moles from grams/molar mass.
You convert g to kg by dividing by 1000 (moving the decimal point to the left three places).
The density equation is
mass = volume x density.
~for M i got 2.28M
my calculation: M=2.28/1
but the ans is 1.92M.
~for the mass% i got 12.31%
my calculation: mass%=133/1080x100%
but the ans is 10.4%