1 / 19

Gas Laws

Gas Laws. Robert Boyle. Jacques Charles. Amadeo Avogadro. Joseph Louis Gay-Lussac. Boyle’s Law. Pressure is inversely proportional to volume when temperature is held constant.

goro
Download Presentation

Gas Laws

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Gas Laws Robert Boyle Jacques Charles Amadeo Avogadro Joseph Louis Gay-Lussac

  2. Boyle’s Law Pressure is inversely proportional to volume when temperature is held constant.

  3. 1 A diver’s lungs hold about 20.0 L of air underwater at a pressure of 875 mm Hg. Assuming he holds his breath and his lungs don’t burst, what will be the volume of air in his lungs at standard pressure on the water’s surface. A. 20.0 L B. 30.2L C. 23.0 L D.87.5 L

  4. The volume of a gas is directly proportional to temperature, and extrapolates to zero at zero Kelvin. (P = constant) Charles’s Law Temperature MUST be in KELVINS!

  5. 2. A shampoo bottle contains 443 mL of air at 65C. What is its volume when it cools to 22C? A. 386.6 ml B. 4.3 L C. 350.0 ml D.700.4 ml

  6. Gay Lussac’s Law The pressure and temperature of a gas are directly related, provided that the volume remains constant. Temperature MUST be in KELVINS!

  7. 3. When a canning jar is sealed at 100C the pressure inside is 101.3 kPa. What is the pressure inside the jar when it cools to room temperature, about 21C? A. 100 atm B. 200 Kps C. 84.0 kpa D. 79.8 Kpa

  8. The Combined Gas Law The combined gas law expresses the relationship between pressure, volume and temperature of a fixed amount of gas.

  9. 4. A sample of propane has a volume of 250.0 L at 125 kPa and 38C. What volume will this sample have at 100.0 kPa and 95C? A. 370 . 0 L B. 100 . 0 L C. 250.3 L

  10. PV = nRT P = pressure in atm V = volume in liters n = moles R = proportionality constant = 0.08206 L atm/ mol·K T = temperature in Kelvins Ideal Gas Law Holds closely at P < 1 atm

  11. 5. A balloon is filled with helium to a volume of 12.5 liters at 25C and 1.01 atm. How many grams of helium are in the balloon? A. 2.07 . g B. .52 g C. 4.04 g

  12. Gas Density … so at STP…

  13. Density and the Ideal Gas Law Combining the formula for density with the Ideal Gas law, substituting and rearranging algebraically: M = Molar Mass P = Pressure R = Gas Constant T = Temperature in Kelvins

  14. Gas Stoichiometry #1 If reactants and products are at the same conditions of temperature and pressure, then mole ratios of gases are also volume ratios. 3 H2(g) + N2(g)  2NH3(g) 3moles H2 +1mole N2 2moles NH3 3liters H2 + 1liter N2 2liters NH3

  15. Gas Stoichiometry #2 How many liters of ammonia can be produced when 12 liters of hydrogen react with an excess of nitrogen? 3 H2(g) + N2(g)  2NH3(g) 12 L H2 2 L NH3 = L NH3 8.0 3 L H2

  16. Gas Stoichiometry #3 How many liters of oxygen gas, at STP, can be collected from the complete decomposition of 50.0 grams of potassium chlorate? 2 KClO3(s)  2 KCl(s) + 3 O2(g) 50.0 g KClO3 1 mol KClO3 3 mol O2 22.4 L O2 122.55 g KClO3 2 mol KClO3 1 mol O2 = 13.7 L O2

  17. Gas Stoichiometry #4 How many liters of oxygen gas, at 37.0C and 0.930 atmospheres, can be collected from the complete decomposition of 50.0 grams of potassium chlorate? 2KClO3(s)  2KCl(s) + 3O2(g) 50.0 g KClO3 1 mol KClO3 3mol O2 0.612 = mol O2 122.55 g KClO3 2mol KClO3 = 16.7 L

  18. For a mixture of gases in a container, PTotal = P1 + P2 + P3 + . . . Dalton’s Law of Partial Pressures This is particularly useful in calculating the pressure of gases collected over water.

  19. Partial Pressures • 6) A vessel contained N2, Ar, He, and Ne. The total pressure in the vessel was 987 torr. The partial pressures of nitrogen, argon, and helium were 44.0, 486, and 218 torr, respectively. The partial pressure of neon in the vessel was __________ torr. • A) 42.4 • B) 521 • C) 19.4 • D) 239

More Related