Question

12 J dz. 1,26 g/L 16. Oxygen has a density of 1.43 g/L at STP. What is the density of oxygen at -33° C and 650. mm Hg? 17. A partially filled weather balloon contains 1000. cubic feet (ft3) of helium at 23 °C and 1.00 atm. What is the air temperature when the balloon reaches a height where the pressure is 0.660 atm and the volume of the balloon has expanded to 1.20 x 103 cubic feet?! Instructors Initials

Answer 1

y 143 g/L at STP. Answer: Given that, for oxygent gos has a density 1:43 g/La We have to calculate the density of O2 gas de -33% and 650 mm. ito. So, fi - density at STP = 1:43 g/L. T = initial temp = 0°c = 273k P = initial pressure 2 760 mmity P2 - Final pressure = 650 mm Hg To a tempo =-33 c = (273-33) k = 240K Now, we know that for ideal gas (02) density, Isa PM where, - M = molar mass Ra Radbeng Constanta

=> f = 8, XP >>$, - (1.43914) x 650 mming x 278 K - 1 P = 1.39914 Hence, the required density of O2 gas at - 33°C and 650 mm Hg is 2.39 glw St0