The mass of one mole of any substance is numerically equal to its relative formula mass or relative atomic mass For example, one mole of carbon is 12 g and contains 6 × 10 23 atoms of carbon.

work out the total relative formula mass or relative atomic mass of the reactants. relative atomic mass of Zn = 65.4 relative formula mass of HCl = 1.0 + 35.5 = 36.5 total relative formula mass of ...