An element X forms an iodide (Xl3) and a chloride (XCl3). The iodide is quantitatively converted to

Question:

An element X forms an iodide (Xl3) and a chloride (XCl3). The iodide is quantitatively converted to the chloride when it is heated in a stream of chlorine:
2 XI3 + 3 Cl2 → 2 XCl3 + 3 I2
If 0.5000 g of Xl3 is treated, 0.2360 g of XCl3 is obtained.
(a) Calculate the atomic weight of the element X.
(b) Identify the element X.