Agenda: 4/22

2. Agenda: 4/22 • Gases & Gas Laws • Purpose: To use mathematical formulas to predict how a gas will change • Warm-up: Stoichiometry Problems with Gases • States of Matter • Kinetic Molecular Theory • Measurements used in Gas

3. Essential to StoichiometrySet-up of problems The mole ratio is the heart of the stoichiometry calculation

4. Stoichiometry Calculations Mole Ratio Mole________ Mole Volume of a Gas Volume of a Gas Mass Mass X Mole Mole Particles Particles

5. Stoichiometry Problem • To produce ammonia, nitrogen gas reacts with hydrogen gas. • Write the balanced chemical equation: • Calculate: • How many liters of ammonia will be produced if there are 10 moles of nitrogen gas (and plenty of hydrogen gas for the reaction to proceed)? • How many liters of hydrogen gas will be needed to react with 25 liters of nitrogen gas?

6. Gases Unit 8 Essential Standards: 2.1.5 Chapters 13 & 14 Purpose: To use mathematical formulas to predict how a gas will change

7. Gas Laws (Formulas) Gas molecules act in orderly and predictable ways. - We can use mathematical formulas to predict what they will do when we change Temperature, Pressure, or Amount.

8. Review: What are gases? Describe the location & movement of the particles at each state of matter? How are gases different?

9. What are gases? How are they different?Describe the gases in terms of size and type of compound (bond type).

10. Elements that exist as gases at 250C and 1 atmosphere

11. Differentiating gases from solids and liquids • Kinetic Molecular Theory • or “Why solids, liquids and gases behave as they do” • How are gases different?

12. Differentiating gases from solids and liquids • Kinetic Molecular Theory • or “Why solids, liquids and gases behave as they do” • All matter is made of __________________ and these are always in _________________. • Temperature determines the ____________ of the ___________________. There are 3 states of matter on earth: _______, ________________, __________________.

13. Gas Behavior – Kinetic Molecular Theory • http://ed.ted.com/lessons/describing-the-invisible-properties-of-gas-brian-bennett • 5 characteristics of gases • - • - • - • - • - http://education-portal.com/academy/lesson/the-kinetic-molecular-theory-properties-of-gases.html#lesson

14. Chemical particles (atoms, molecules, or compounds) act differently when they are in different states of matterPHET – States of Matter – Basicshttps://phet.colorado.edu/en/simulation/states-of-matter-basicsAnimation – http://www.pbs.org/wgbh/nova/physics/states-of-matter.htmlIncludes Temperature & Pressure; Water, Carbon dioxide and hydrogen gas animations Heating curve KMT- Solid KMT-Liquid KMT- Gas

15. Ways we measure gases:

16. Celcius Kelvin Gas Temperature: Always use Kelvin

17. Temperature Conversions • Convert 25.0℃ to Kelvin • Convert 375K to ℃ • Convert -50℃ to K

18. Pressure • http://www.dlt.ncssm.edu/Tiger/chem3.htm • http://education-portal.com/academy/lesson/pressure-and-temperature-conversions.html#lesson Animation Atmospheric pressure You Tube – Atmospheric Pressure http://www.youtube.com/watch?v=xJHJsA7bYGc

19. Air Pressure of the Atmosphere 10 miles 0.2 atm 4 miles 0.5 atm Sea level 1 atm

20. Force Area Barometer Pressure = Units of Pressure Or 760 mm of Mercury 1 atm = 760 mmHg = 760 torr 1 atm = 101 kPa (101,325 Pa)

21. Measuring Pressure: Units

22. STP = Standard Temperature & Pressure What does the chemistry reference table tell you? • STP= 1 atm at 0°C or _________ K • = __________mm Hg • = __________ KPa • = __________ torr Standard Molar Volume of a Gas: 1 mole = ______ Liter (volume occupied by one mole of any gas at STP = ______ Liter)

23. Pressure Conversions • Convert 98.35 kPa to atm • Convert 745 mm Hg to atm • Convert 740 mm Hg to kPa

24. Gases act in predictable ways so we can use mathematical formulas to determine how they act Gas Laws Shows the relationship of volume. Temperature, pressure and quantity of molecules in mathematical terms

25. http://phet.colorado.edu/en/simulation/gas-properties

26. Three Major Laws Combined Gas Law P₁V₁= P₂V₂ T₁ T₂ Ideal Gas Law PV = nRT • Dalton’s Law of Partial Pressure Ptotal = P₁+P₂+P₃+Petc.

27. “A Rational Equation” means an equation which uses ________.

35. Need variable cards Isolating the Unknown Variable P₁V₁ = P₂V₂ T₁ T₂ We can slide diagonally across the equal sign without changing the mathematical relationship.

36. Isolating the Unknown Variable P₁V₁ = P₂V₂ T₁ T₂ We can slide diagonally across the equal sign without changing the mathematical relationship.

37. Isolating the Unknown Variable P₁V₁ = P₂V₂ T₁ T₂ We can slide diagonally across the equal sign without changing the mathematical relationship.

38. Isolating the Unknown Variable P₁V₁ = P₂V₂ T₁ T₂ We can slide diagonally across the equal sign without changing the mathematical relationship.

39. Combined Gas Law

40. Combined Gas Law P₁V₁ = P₂V₂ T₁ T₂

41. Combined Gas Law: Example A gas at 110 kPa and 30℃ fills a flexible container with an initial volume Of 2.00L. If the temperature is raised to 80℃ and the pressure increased To 440 kPa, what is the new volume? P₁V₁ = P₂V₂ T₁ T₂ Answer: 0.58L

42. Combined Gas Law P₁V₁= P₂V₂ T₁ T₂ Keeping one variable constant:

43. Boyles’ Law Animation • http://group.chem.iastate.edu/Greenbowe/sections/projectfolder/flashfiles/gaslaw/boyles_law_graph.html

44. Boyles’ Law: Vary P & VUses: bicycle pump; syringe for injections; popping a balloon by squeezing; Scuba diving: increase in bubble size as rise to surface of water Others? P₁V₁ = P₂V₂ T₁ T₂

45. Boyles’ Law: ExampleA cylinder of oxygen has a volume of 2.0L. The pressure of the gas is 10 atm at 0℃. What will be the volume at STP? P₁V₁ = P₂V₂ T₁ T₂

46. Boyles’ Law: Practice Problems P₁V₁ = P₂V₂ T₁ T₂

47. Boyles’ Law: Practice Problems P₁V₁ = P₂V₂ T₁ T₂

48. Charles’ Law – animation • http://group.chem.iastate.edu/Greenbowe/sections/projectfolder/flashfiles/gaslaw/charles_law.html

49. http://phet.colorado.edu/en/simulation/gas-properties

50. Charles’ Law: Vary V & TUses: Hot Air BalloonsDecorating with party balloons; Cooked turkey monitor/device; Playing basketball on a cold day P₁V₁ = P₂V₂ T₁ T₂