How many moles of oxygen are in 52.5 grams of oxygen gas?

An oxygen gas is a diatomic molecule which means that each molecule is composed of 2 atoms. Its symbol is O2. 

Each oxygen atom has a molar mass of 16 g/mol. The molar mass of oxygen gas is calculated below,
                         molar mass = 2 x (16 g/mol) = 32 g/mol

To determine the number of moles in 52.5 grams of oxygen, divide the given mass by the calculated molar mass.
 
                                 n = 52.5 grams / (32 gram/ mol)
                                     n = 1.64 moles

Thus, there are 1.64 moles of oxygen gas.