The term used for the molecular (formula) mass of any substance expressed in grams is Molar mass.
The molar mass of an element (or compound) is the mass in grams of 1 mole of that substance, a property expressed in units of grams per mole (g/mol).
on the other hand
Molar volume is the volume occupied by 1 mol of a compound (or element) at a given temperature and pressure.SI unit is (m³/mol).
Avogadro's number, or Avogadro's constant, is the number of particles found in one mole of a substance. It is the number of atoms in exactly 12 grams of carbon-12. It is represented by L.
L= 6.0221 x 1023 particles.
Mole is an SI unit used to measure the amount of any substance.