To solve for the number of moles, we simply have to use
the Avogadros number which states that there are 6.022 x 10^23 molecules per
mole. Therefore:
number of moles = 6.67 X 10^40 chlorine molecules / (6.022
x 10^23 molecules / mole)
number of moles = 1.108 x 10^17 moles
