Question

determine the empirical formula of the compound formed when 1.2g of magnesium reacts with 3.55g of chlorine.take the molar mass of magnesium and chlorine to be 24g and 35.5g.​

Answer 1

Answer:  MgCl2

Explanation:

Convert the masses of Mg and Cl to moles:

Mg:  1.2g/24g/mole = 0.050 moles

Cl:    3.55g/35.5g/mole = 0.100 moles

The ratio of Cl to Mg is 2 to 1:  (0.100 moles Cl/0.050 moles Mg),  Therefore there must be 2 Cl for every Mg:

MgCl2

This is the empirical formula since all we know is the ratio.  If could also be Mg2Cl4, Mg3Cl6, etc,  [i.e., (MgCl2)n]