1 / 27

Gas Laws

Gas Laws. The work of Boyles, Charles, Dalton, Graham and other scientists explains the behavior of gases. . High temperatures and low pressures. Kinetic Molecular Theory. Explanation of how IDEAL gas particles behave move in constant, random, straight-line motion

reuben
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 The work of Boyles, Charles, Dalton, Graham and other scientists explains the behavior of gases.

  2. High temperatures and low pressures Kinetic Molecular Theory • Explanation of how IDEAL gas particles behave • move in constant, random, straight-line motion • undergo “elastic” collisions • transfer energy • Particles are volumeless • no intermolecular attractions

  3. Deviations from Ideal Behavior • No gas behaves perfectly all the time • Major deviations are seen at low temperatures COLD and high pressures SQUEEZED • Lose E • Attractions form between particles • Not in constant motion • Particles have volume

  4. You know gases are behaving like ideal gases if they mathematically conform to these gas laws.

  5. Boyle’s Law constant (T)emperature • Relationship between (P)ressure and (V)olume

  6. A decrease in volume results in an increase in pressure

  7. Inverse relationship • P1V1=P2V2= P3V3. . .constant value

  8. Practice P1V1 = P2V2 • A sample of gas under a pressure of 822kPa has a volume of 312ml. The pressure is increased to 948kPa. What volume will the gas occupy? • The volume of a gas is .2L when the pressure is 9.25atm. If the volume is increased to 306mL what is the new pressure?

  9. Charles’ Law

  10. Charles’ Lawconstant pressure • Relationship between temperature and volume • Volume of a Balloon

  11. V T Volume is directly proportional to Temperature in Kelvin K = oC + 273 V  T V  T

  12. Volume Temperature K Constant pressure graph V1/T1 = V2/T2

  13. Practice • A sample of a gas has a volume of 152mL when its temperature is 18oC. If its temperature is increased to 32oC, what will the volume become?

  14. Relationship between Temperature and Pressureconstant volume • As the molecules move faster they collide more with the walls of their container  P if volume remains the same P1/T1 = P2/T2

  15. Practice • At a temperature of -33.0oC, a sample of confined gas exerts a pressure of 53.3kPa. If volume remains constant, at what temperature will the pressure reach 133kPa?

  16. V P Gas Lawssummary

  17. It is often necessary to determine relationships between (P)ressure (V)olume (T)emperature Kelvin! P1V1 = P2V2 T1 T2 COMBINEDGas Laws

  18. Practice • A sample of oxygen gas has a volume of 205mL when its temperature is 22.0oC and its pressure is 30.8kPa. What volume will the gas occupy at STP?

  19. Remains the same Density of Gas • The density of a gas varies widely depending on temperature and pressure D = m/v

  20. Hints to Density problems • Write down everything known and unknown in the problem • Before you find D you must find V2 • If D is given, immediately find mass and volume if D=5g/L then m=5g v=1L • Mass stays constant • If no mass is given do STOICH!

  21. Avogadro’s Law • Equal volumes of gases under the same conditions of temperature and pressure contain the same number of molecules. • Lower volume: less molecules • Higher volume: more molecules

  22. You can only compare volumes (number of molecules) WHEN the samples are at the SAME TEMPERATURE AND PRESSURE So you may have to do the math! • Which container has the least number of molecules? 4L of CO2 at STP 3L of N2 at 2atm & 20oC

  23. Dalton’s Law • In a containerwhere a mixture of gases is present, the total pressure of the mixture is equal to the sum of the partial pressures for each of the gases • PTotal = P1 + P2 + P3 . . .

  24. A 600mL container is filled with 200mL of hydrogen and 400mL of oxygen. The total pressure in the container is 75kPa, what is the partial pressure of each gas? 25kPa = Hydrogen 50kPa = Oxygen There is twice as much oxygen so it exerts twice as much pressure

  25. Graham’s Law • Molecules of higher molecular mass diffuse more slowly as compared to molecules of lower molecular mass. F2 Cl2 H2 Ne Kr

  26. The End

More Related