[au5467]

Here's the question:
If 55.0% of molecules are CH₂Cl₂ in 100.0ml mixture of CH₂Cl₂ (density=1.33g/ml) and CHCl₃ (density=1.48g/ml), what is the mole fraction of CHCl₃?

I tried assuming that in a 100grams of mixture, there would be 55.0ml of CH2Cl2... and 45.0ml of CHCl3. I then used the densities given to get my final answer--0.393--but this was not in the answer choice. I'm stuck. Do I use 55.0g CH2Cl2 and 45.0g CHCl3 instead?
I'm not sure if I am at the right starting point. Please help me!!

The answer choices: 0.35     0.45      0.52     0.55     0.65

I know that mole fraction= mol of A/(mole of A + mol of B)

[Borek]

Can you relate number of molecules to number of moles?