The vapour pressure of a saturated solution of sparingly soluble salt `("XCl"_(3))` was 17.20mm Hg at `27^(@)"C"`. If the vapour pressure of pure `"H"_(2)"O"` is 17.25 mm Hg at 300K, what is the solubility of sparingly soluble salt `"XCl"_(3)" in mole"//"Litre".`