I need to determine the "percentage composition unknown" whatever that is. My current data: a) mass of test tube and foil cover: 7.5323 g b)temp of water bath: 375.65 K c) mass of test tube and foil and gas as sample: 7.5423 g d) barometric pressure: 1.0190 kpa e) mass of test tube and foil and water: 15.4012 g

Please help me. Chemistry is not my forte.