Calculate the number of molecules of oxygen in a 5.45×105 g sample of oxygen.

Answer 1

An oxygen molecule is O₂, i.e. it is diatomic. The molar mass is 32 g/mol.

5.45x10⁵ g x 1 mol / 32 g x 6.02x10²³ molecules/mol = 1.03x10²⁸ molecules of O₂