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

Step-by-step 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]