10 billion oxygen molecules (1 x 1010) is how many moles of molecular oxygen are there?
To calculate the number of moles of a substance, you need to divide the number of molecules by Avogadro's number (6.022 x 10^23 molecules/mol).
Number of moles = Number of molecules / Avogadro's number
Number of moles = 1 x 10^10 / 6.022 x 10^23
Number of moles = 1.661 x 10^-14 moles
Therefore, there are approximately 1.661 x 10^-14 moles of molecular oxygen in 10 billion oxygen molecules.