Chapter 2, Problem 31P

An element X has a dibromide with the empirical formula ${\text{XBr}}_{\text{2}}$ and a dichloride with the empirical formula ${\text{XCl}}_{\text{2}}$ .The dibromide is completely converted to the dichloridewhen it is heated in a stream of chlorine according to thereaction

${\text{XBr}}_{\text{2}}+{\text{Cl}}_{\text{2}}\to {\text{XCl}}_{\text{2}}{\text{1Br}}_{\text{2}}$

When 1.500 g ${\text{XBr}}_{\text{2}}$ is treated, 0.890 g ${\text{XCl}}_{\text{2}}$ results.

(a) Calculate the atomic mass of the element X.

(b) By reference to a list of the atomic masses of the elements,identify the element X.