moles are amount of substance. Molar mass is the mass of 1 mol of substance.
Molar mass of LiCl is the sum of molar masses of the individual elements.
molar mass of Li - 6.9 g/mol and Cl - 35.45 g/mol
molar mass of LiCl - 6.9 + 35.45 = 42.35
therefore molar mass of LiCl - 42.35 g/mol
number of moles of LiCl = mass present / molar mass of LiCl
number of LiCl moles = 250 g / 42.35 g/mol = 5.90 mol
5.90 moles of LiCl
