The most water on earth is held by the oceans .
1 mol = 6.023x10^23 number of molecules (Avogadro's number)
1 : 6.023x10^23
X : 4.91x10^22
(6.023x10^23)X = 4.91x10^22
X = 4.91x10^22/6.023x10^23
X = 0.082 Moles
Helium would be the least I think
The formula for the molecular formula is molar mass/ empirical formula
So, the empirical formula of C3H7 is equal to C*3 + H*7 which is equal to 12*3 + 7. Then use the molecular formula = 86 / (12*3+7) = 2
Therefore, the molecular formula is 2 times the empirical formula which is C6H14.