1 / 19

Gases An Exploration in Ideal Gas Behavior

Gases An Exploration in Ideal Gas Behavior. Loosely adapted from: Philip Dutton University of Windsor, Canada and Martin Silberberg. Some Important Industrial Gases. Name (Formula) Origin and use. Methane (CH 4 ) Natural deposits; domestic fuel

sian
Download Presentation

Gases An Exploration in Ideal Gas Behavior

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. GasesAn Exploration in Ideal Gas Behavior Loosely adapted from: Philip Dutton University of Windsor, Canada and Martin Silberberg

  2. Some Important Industrial Gases Name (Formula) Origin and use Methane (CH4) Natural deposits; domestic fuel Ammonia (NH3) From N2 + H2 ; fertilizers, explosives Chlorine (Cl2) Electrolysis of seawater; bleaching and disinfecting Oxygen (O2) Liquified air; steelmaking Ethylene (C2H4) High-temperature decomposition of natural gas; plastics

  3. Substances That Are Gases under Normal Conditions Substance Formula MM(g/mol) Helium He 4.0 Neon Ne 20.2 Argon Ar 39.9 Hydrogen H2 2.0 Nitrogen N2 28.0 Nitrogen monoxide NO 30.0 Oxygen O2 32.0 Hydrogen chloride HCl 36.5 Ozone O3 48.0 Ammonia NH3 17.0 Methane CH4 16.0

  4. The Three States of Matter

  5. Important Characteristics of Gases 1) Gases are highly compressible An external force compresses the gas sample and decreases its volume; removing the external force allows the gas volume to increase. 2) Gases are thermally expandable When a gas sample is heated, its volume increases; when it is cooled its volume decreases. 3) Gases have low viscosity Gases flow more easily than liquids or solids.

  6. Important Characteristics of Gases 4) Most Gases have low densities Gas densities are on the order of grams per liter whereas liquids and solids are grams per cubic cm, 1000 times greater. 5) Gases are infinitely miscible Gases mix in any proportion. An example of such is air, a mixture of many gases.

  7. Force (N) P (Pa) = Area (m2) Properties of Gases: Gas Pressure • Gas Pressure • Liquid Pressure P = g ·h·d

  8. Pressure of the Atmosphere • Called “atmospheric pressure,” or the force exerted upon us by the atmosphere above us. A measure of the weight of the atmosphere pressing down upon us. • Measured using a barometer - A device that can “weigh” the atmosphere above us. Force Area Pressure =

  9. A Mercury Barometer

  10. Effect of Atmospheric Pressure on Objects at the Earth’s Surface

  11. Construct a Barometer Using Water dwater = 1.00 g/cm3 dHg = 13.6 g/cm3 Height of water column = Hw …of Hg column = HHg HW = 10.3 m = 33.8 ft

  12. The Mystery of the Suction Pump Because of the density of water, a “suction” pump can only pull water from a maximum depth of ~10 m (~34 feet) regardless of the quality of the vacuum or how fast the handle is pumped. For wells deeper than 34 feet, the water must be pushed up from below.

  13. Manometers

  14. Common Units of Pressure Unit Atmospheric Pressure Scientific Field pascal (Pa); 1.01325 x 105 Pa SI unit; physics, kilopascal(kPa) 101.325 kPa chemistry atmosphere (atm) 1 atm* Chemistry millimeters of mercury 760 mmHg* Chemistry, medicine, ( mm Hg ) biology torr 760 torr* Chemistry pounds per square inch 14.7 lb/in2 Engineering ( psi or lb/in2 ) bar 1.01325 bar Meteorology, biology chemistry, physics

  15. Converting Units of Pressure Problem: A chemist collects a sample of carbon dioxide from the decomposition of limestone (CaCO3) in a closed end manometer, the height of the mercury is 341.6 mm Hg. Calculate the CO2 pressure in torr, atmospheres, and kilopascals. Solution: converting from mmHg to torr: 1 torr 1 mm Hg PCO2 (torr) = 341.6 mm Hg x = 341.6 torr converting from torr to atm: 1 atm 760 torr PCO2( atm) = 341.6 torr x = 0.4495 atm converting from atm to kPa: 101.325 kPa 1 atm PCO2(kPa) = 0.4495 atm x = 45.54 kPa

  16. Characterization of a Gas Sample To fully characterize any gas sample, 4 variables must be accounted for: Pressure (P) Volume (V) Quantity of gas in moles (n) Kelvin Temperature (T)

  17. Experiment this week Determine the relationship between: P and V P and T

  18. Vernier Pressure Sensor Note: Pressure must not exceed 220 kPa. Start with syringe at 10 mL and compress no further than 5 mL. Draw plunger back to get larger volumes. Set up LoggerPro to collect data on command: Experiment | Data Collection Change Mode: Events with Entry Lots of little parts. Please don’t lose them. Use a 60 mL syringe rather than the 20 mL supplied in the box. Attach syringe to Leur-lock with a gentle push… …then a gentle twist. It doesn’t have to be really tight. Really, it doesn’t. A Note on Pressure Versus Temperature: What must be constant? Use a small Erlenmeyer flask and the plastic tubing to attach the sensor. Clamp the flask below the surface of water in a big beaker. Use ice for subambient temperatures. Heat to no hotter than about 80°C

  19. Other Notes The thermometers don’t know how to swim! • Please don’t teach them This investigation, Author 2: Introduction and Conclusion 3: Discussion 1: Data/Results and Experimental This investigation, Author B: Introduction, Conclusion, Data/Results A: Discussion and Experimental

More Related