Answer: 32 g/mol
Step-by-step explanation:
According to Avogadro's law, 1 mole of every substance contains avogadro's number
of particles and weighs equal to its molecular mass.
Diatomic molecule is a molecule formed by combination of two atoms of the same element. Example:

1 mole of oxygen
molecule contains = 2 moles of oxygen atoms
1 mole of oxygen atom weigh= 16 g
2 moles of oxygen atoms weigh =

Thus 1 mole of oxygen molecule weigh 32 g.