3 L and at a temperature of 32C exerts a pressure 47 atm Calculate the number

# 3 l and at a temperature of 32c exerts a pressure 47

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A sample of nitrogen gas kept in a container of volume 2.3 L and at a temperature of 32°C exerts a pressure 4.7 atm. Calculate the number of moles of gas present. (8 points) 1 Copyright © 2016 by Thomas Edison State University . All rights reserved. PV=nRT 4.7 atm x 2.3 L = n x .0821*305K 10.81 = n x 25.04 N = .43 mols (Reference: Chang 5.31) 5.What volume will 5.6 moles of sulfur hexafluoride (SF6) gas occupy if the temperature and pressure of the gas are 128°C and 9.4 atm? (8 points) 6. A gas-filled balloon having a volume of 2.50 L at 1.2 atm and 25°C is allowed to rise to the stratosphere (about 30 km above the surface of Earth), where the temperature and pressure are –23°C and 3.00 × 10 –3 atm, respectively. Calculate the final volume of the balloon. (8 points) (Reference: Chang 5.35) 1.2 atm x 2.50L/ 298K = 3.00x10 -3 atm x V2 / 250K 0.0007 x 250K = 2.5175 / 3.00 x 10 -3 atm = 8.39x10 -4 = 839 L 7. A 2.10-L vessel contains 4.65 g of a gas at 1.00 atm and 27.0°C. (a) Calculate the density of the gas in grams per liter. (b) What is the molar mass of the gas? (10 points) (Reference: Chang 5.47) PV/RT= 1.00 x 2.10 / .08206 x 300 = .0853 4.56g / .0853mol = 54.5g/mol 54.5 x 1.00 / .08206 x 300 = 2.21g/L 8. A certain anesthetic contains 64.9 percent carbon, 13.5 percent hydrogen, and 21.6 percent oxygen by mass. At 120°C and 750 mmHg, 1.00 L of the gaseous compound weighs 6.90 g. What is the molecular formula of the compound? (10 points) PV=nRT n=PV/RT= (0.987 atm x 1.00 L)/(0.082 x 392.3 K) = 0.0307 mols mols = mass/mw 0.0307 mols = 6.90 / mw  #### You've reached the end of your free preview.

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