Calculate the number of moles of magnesium present in a magnesium ribbon weighing 12 g. Molar atomic mass of magnesium is 24g mol–1.


The number of moles =
n =

Here, n = Number of moles


M = Given mass


M = Molar mass


Thus, the number of moles of magnesium (Mg) =


n = 0.5mole


24