How many atoms are in 5.0 moles copper?
You could have asked how many copper atoms exist in 6 dozen copper atoms....clearly the answer is 72. Instead of the dozen, we use another collective number,
And so we take the PRODUCT....
Can you tell me (with reference to something else) the MASS of the given molar quantity? And if you can understand this you understand molar equivalence to degree level. Congratulations.