Now to solve this problem, we are given the number of atoms
therefore we must first convert this into number of moles. We can do this by
using the Avogadro’s number. Calculating for number of moles of Carbon:
number of moles Carbon = 21 atoms of carbon (1 mole / 6.022
x 10^23 atoms C)
number of moles Carbon = 3.49 x 10^-23 mol C
Converting this to mass by multiplying the molar mass of
C:
mass Carbon = 3.49 x 10^-23 mol C (12 g / mol)
mass Carbon = 4.18 x 10^-22 g
Therefore the mass of one molecule of Cortisone is:
mass of 1 molecule Cortisone = 4.18 x 10^-22 g / 0.6998
mass of 1 molecule Cortisone = 5.98 x 10^-22 g per molecule
Converting this to mass per 1 mol of Cortisone, by using
again the Avogadro’s number:
mass of 1 mol Cortisone = (5.98 x 10^-22 g / molecule) (<span>6.022
x 10^23 molecules / mol)</span>
mass of 1 mol Cortisone = 360.10 g / mol = molar mass of
cortisone
Answer:
360.10 g / mol
