Question

Find mole 12g of oxygen is given

Answer 1

12g of oxygen has 12/16 moles.
as moles are given mass/molar mass.

Answer 2

Helloo!!

Mole = given mass / molecular mass

here given mass of oxygen is 12 gram
and molecular mass of oxygen is 16 gram

then mole = 12/16
= 0.75

hope it helps