Explanation: Molar mass in chemistry is the mass of a sample of a compound divided by the amount of substance in that compound. In other words, the molar mass is the mass expressed in grams of one mole of substance. If according to the SI system the basic unit for the amount of the substance is mole, and if one mole of Na has a mass of 22.98977 grams, then we will find a mass of 0.5 moles of Na, if we multiply 0.5 moles of Na with the mass of one mole of Na, i.e. with 22.98977 grams.
In other words, the mass of 0.5 moles of sodium is equal:
(0.5 moles of Na) x (22,98977 grams of one moles of Na) = 11, 494885 grams