Dear
Momina4468;
“A mole of Nitrogen” is simple an “Undetermined Expression”!
“
Mole” looks like a Quantity but it is a Unit, more precisely a
SI Base Unit.
That’s why an expression with mole should contain a numeric value, like one, or 3.25 or 0.0613 or so.
You may also read: "
Mole (unit)”
Good Luck!
ARGOS
++