I am still having a little problem with my original question. However, this is what I have done so far.

Question

I am not sure what to do with the density of the solution of 0.78 g/mL.
The answer I came up with is 5.47 mol/kg. I found the density of the water in grams then I converted it to kg (152 x .001 = .152. I divided 50 g by the molar mass of 60.09502 g/mol = .8320 moles. Next, I divided that by .152. However, I didn't use the .78 g/mL beacause I am not sure what to do with it. Please explain.

ORIGINAL QUESTION - what is the molality of a solution of 50.0 grams of propanol in 152 mL water if the density of wate is 1.0 g/mL and the density of the solution is 0.78 g/mL

Answer 1

I answered this for you last night just before retiring to bed. You don't need the 0.78 g/mL density of the solution. The answer is 5.47 molal. The question was to determine the molality of the solution; 5.47 m (mol/kg is molality) is the correct answer.

Answer 2

i have this question for an online assignment and it keeps telling me that 5.47 is wrong. so my guess is that you do need the density...just saying