Question

6g of metal M reacts completely with 23.66g of Chlorine to form 29.66g of the metallic chloride. find the empirical formula of the metallic chloride. (M=27, Cl=35.5)

Answer 1

According to the law of equivalents:

$$m(M) : m(Cl_2) = M_{eq}(M) : M_{eq}(Cl_2)$$ $$M_{eq} (Cl_2) = m(Cl_2)/z = 71/2 = 35.5 mol$$ $$6 : 23.66 = M_{eq}(M) : 35.5$$ $$M_{eq}(M) = 9 g/mol$$

If the molar mass of the metal element is 27, then the equivalence number:

$$z(M) = 27/9 = 3$$

$$z(Cl_2) = 2$$

$$z(Cl) = 1$$

Then the empirical formula of metal chloride:

$$MCl_3$$

Answer: MCl₃