Estimation+of+Avogadoro's+Number

I was pondering the oil drop experment and wondering if it might be possible to estimate the size of a mole from the oil drop/talc powder experiment. So I looked at the class data

Thickness 8.6E-7 cm 2.69E-7 cm 1.2E-7 cm 7.5E-8 cm 7.6E-8 cm

1) assume molecule is a box with equal dimensions. (I know it probably is vertical, but it's an estimation) 2) volume of a molecule is then thickness to the third power. 3) assume olive oil is oleic acid (its 65-80%). 4) If 1g of H is a group, then 282 g of C18H34O2 is also a group. 5) The density of oleic acid is 0.895 g/cm^3 The problem is now just unit analysis

282 g/group * 1 cm^3/0.895g * #molecules/cm^3 = X #atoms/group

Answers vary as the thickess varied to the third power, but here they are for our class. 5 x 10^20 1.6 x 10^22 1.8 x 10^23 7.5 x 10^23 7.2 x 10^23

Richard Daines