1 / 8

Boyle’s Law

Boyle’s Law. The volume of a fixed mass of gas varies inversely with the pressure at constant temperature . PV = k P 1 V 1 = P 2 V 2. Episode 902. Kinetic Theory and Boyle’s Law. Pressure of a gas is caused by the molecules of the gas striking the walls of the container .

kent
Download Presentation

Boyle’s Law

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. Boyle’s Law • The volume of a fixed mass of gas varies inversely with the pressure at constant temperature. • PV = k • P1V1 = P2V2 Episode 902

  2. Kinetic Theory and Boyle’s Law • Pressure of a gas is caused by the molecules of the gas striking the walls of the container. • If the gas is compressed to half the volume it had, twice as many molecules are present in any given volume. • Twice as many impacts per second on the walls of the container • Pressure of the gas will double Episode 902

  3. Example 1 • A balloon filled with helium has a volume of 457 mL at standard atmospheric pressure. After the balloon is released, it reaches an altitude of 6.3 km where the pressure is only 65.5 kPa. What is the volume of the balloon at this altitude? • Given: • V1 = 457 mL • P1 = 101.3 kPa • P2 = 65.5 kPa • V2 = ? P1V1 = P2V2 (457 mL)(101.3 kPa) = (65.5 kPa)V2 V2 = 707 mL Episode 902

  4. Example 2 • Under a pressure of 623 mm Hg, a confined gas has a volume of 335 mL. If the pressure is increased until the volume is 252 mL, what is the new pressure , assuming the temperature remains constant? • Given: • V1 = 335 mL • P1 = 623 mm Hg • V2 = 252 mL • P2 = ? P1V1 = P2V2 (335 mL)(623 mm Hg) = P2(252 mL) P2 = 828 mm Hg Episode 902

  5. Charles’s Law • For a fixed mass of gas, as long as the pressure is held constant, the volume varies directly with the Kelvin temperature. • V/T = k • V1/T1 = V2/T2 Episode 902

  6. The Kelvin Temperature Scale • Absolute zero • Lowest possible temperature • Never been reached • 0 Kelvin = absolute zero • 0 Kelvin = -273.15 ⁰C • K = 273 + ⁰C Episode 902

  7. Example 1 • A quantity of gas occupies a volume of 506 cm3 at a temperature of 147 ⁰C. Assuming the pressure stays constant, at what temperature will the volume of the gas be 604 cm3? • Given: • V1 = 506 cm3 • T1 = 147 ⁰C • V2 = 604 cm3 • T2 = ? V1/T1 = V2/T2 506 cm3/420 K = 604 cm3/T2 T2 = 501 K or 501 – 273 = 228 ⁰C (420 K) Remember to convert temperature to Kelvin Episode 902

  8. Kinetic Molecular Theory and Charles’s Law • Doubling the Kelvin temperature of a gas doubles the average kinetic energy of its molecules. • Faster moving molecules • Strike the walls of the container more often • Strike the walls of the container with more force • From Boyle’s law we derive that the volume would have to double if the Kelvin temperature is doubled so that the pressure would remain constant. Episode 902

More Related