An element, X, can form a chloride (XCl3) and an iodide (XI3). The chloride can be converted quantitatively into the iodide when exposed to excess heated iodine. If 0.840 grams of XCl3 are treated with iodine, 2.305 g of XI3 are produced. What is the chemical symbol for this element? Use stoichiometry to create an equation that allows you to solve for the molecular weight of X.
2 XCl3 + 3 I2 ---------> 2 XI3 + 3 Cl2