Question

1.) A solution of oleic acid, C17H33COOH, is added one drop at a time onto water until a
monolayer is formed. Assume that there are no spaces between molecules in the monolayer
and that each oleic acid molecule accupies an area of 0.25 nm^2. If the concentration of the
oleic acid solution is 0.00012 g/mL, what is the experimental value of Avogadro's number?

dropper pipet calibration = 68 drops/mL
number of drops of oleic acid in the monolayer = 16 drops
diameter of monolayer = 15.0 cm

Answer 1

this question seems kinda weird, because there is no possible way to count the number of molecules present. so you can't estimate avogadro's number..

But this is what you can do: get the mass by finding the volume and multiplying it by the density. (you know the number of drops and you know the amount of drops to make a mL).

Then to go any further, you have to assume that the molar mass of oleic acid can be found by using the periodic table, but that assumes that you already know avogadro's number, so i'm not sure what after.