Question

A mass of 3.6g of magnesium reacts in excess chlorine to form a chloride. If the mass of the chloride is 14.25g, find the formula of the chloride formed (Mg=24, Cl=35.5)

Answer 1

Mass of chloride used = 14.25 – 3.6g = 10.65g.
Element         Mg          Cl
Mass (g)        3.6         10.65
R.A.M            24          35.5
Moles            3.6         10.65
                       24          35.5
                    0.15           0.3
                    0.15         0.15
Mole ratio 1:2
Formula MgCl₂