A barium halide exists as the hydrated salt BaX2·2H2O, where X is the halogen. 0.2650 g of the salt was dissolved in 200 ml of water and excess sulfuric acid was added. The mixture was then heated and held at boiling for 45 minutes. 0.2533 g of the precipitate, barium sulfate, was filtered off, washed and dried. Determine the identity of the halogen, X.