1 / 13

The Gas Laws

AP Chemistry. The Gas Laws. Basics on Gases. composition of the atmosphere:. ~78% N 2 , ~21% O 2. properties of gases:. expand to fill container compressible form homogeneous mixtures. -- due to gas particles being…. 1). far apart. 2). in constant, random motion.

raya-waters
Download Presentation

The 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. AP Chemistry The Gas Laws

  2. Basics on Gases composition of the atmosphere: ~78% N2, ~21% O2 properties of gases: expand to fill container compressible form homogeneous mixtures -- due to gas particles being… 1) far apart 2) in constant, random motion vapors: gases of substances that are normally liquids or solids e.g., gasoline vapors

  3. F  N Equation for pressure: A  m2 P  N/m2 = Pa 1 atm… = 760 mm Hg = 760 torr = 101.325 kPa = 1.01325 bar (1 bar = 105 Pa) At a depth of 350 m (1150 ft), the hull pressure on a submarine is 3.4 x 106 Pa (36 tons/ft2).

  4. vacuum air pressure mercury (Hg) BAROMETER Close-up of an early mercury barometer, showing how the mercury column is supported by atmospheric pressure. mercury barometer

  5. An aneroid barometer contains a small, pressure-sensitive metal box that has been evacuated of air. The box is prevented from collapsing by being connected to a spring that is also attached to the dial on the barometer. When the air pressure on the walls of the box changes, the box “flexes,” which moves the spring and the dial.

  6. air pressure sealed end Hg height difference confined gas OPEN END MANOMETER CLOSED END MANOMETER SMALL + HEIGHT = BIG Pgas = HEIGHT

  7. The Gas Laws Boyle’s law: PV = constant (when T is constant) Robert Boyle (1627–1691) V V 1/P P

  8. Charles’s law: V/T = constant (when P is constant) Jacques Charles V (1746–1823) **T in K (0.00 K = –273.15oC) T

  9. Gay-Lussac’s law: P/T = constant (when V is constant) P Joseph Louis Gay-Lussac (1778–1850) T

  10. Avogadro’s hypothesis: Equal volumes of gas at the same temperature and pressure have the same number of particles. e.g., 22.4 L of ANY GAS at STP contains 6.02 x 1023 particles Amedeo Avocado Amedeo Avogadro Avogadro’s law: (1776–1856) (1876–1956) Volume of a gas is proportional to the number of moles of gas. i.e.,

  11. Combined Gas law: merges Boyle’s, Charles’s, and Gay-Lussac’s laws into one equation. **NOTE: For all gas law calculations, use the absolute temperature (in K).

  12. Other Equations and Constants Ideal Gas law: R = 8.314 L-kPa/mol-K = 0.08206 L-atm/mol-K P V = n R T Conditions of standard temp. and pressure (STP): 0oC (273.15 K) 1 atm Equations for gas density: M = molar mass of gas same gas; two sets of conditions

More Related