Calculate the number of moles of magnesium, chlorine, and oxygen atoms in 7.80 moles of magnesium perchlorate, Mg (ClO4) 2.

The number of moles of moles of Magnesium, chlorine and oxygen atoms in 7.80 moles of Mg (ClO4) 2 is calculated as below

find the total number of each atom in Mg (ClO4) 2

that is mg = 1 atom

Cl = 1x2 = 2 atoms

O = 4 x2 = 8 atoms

then multiply 7.80 moles with total number of each atom, to get the number moles of each atom

that is

Mg = 7.80 x1 = 7.80 moles

cl = 7.80 x2=15.6 moles

O = 7.80 x8 = 62.4 moles