1. Gas Stoichiometry

2. Random Thoughts 1) We live immersed in a gaseous solution.

3. Random Thoughts 1) We live immersed in a gaseous solution. 2) We live at the bottom of an ocean of air.

4. Random Thoughts 1) We live immersed in a gaseous solution. 2) We live at the bottom of an ocean of air. 3) Pressure goes from High to Low Demo: Low Budget Super soaker Jar with screen

5. Pressure Defined 1) Pressure = Force / Area

6. Pressure Defined 1) Pressure = Force / Area Demo: Nail Board&Cup Holder

7. Pressure Defined 2) Number of collisions of gas molecules on its surroundings.

8. Pressure Defined 2) Number of collisions of gas molecules on its surroundings. Demo: Drink Box Demo: Shrink Wrapping

9. Pressure Defined 3) Really the result of the mass of air being pulled to the center of earth. Gravity

10. Instrument that measures pressure: The Barometer - invented by Torricelli; often used mercury as liquid. --> We get a couple of units from this!

11. The barometer High Pressure or Low? P air ? P gas ?

12. The barometer High Pressure or Low? Gas Inside Outside Air pressure

13. The barometer High Pressure or Low? Gas Inside Outside Air pressure Low pressure=> outside is losing the push vs the inside. P gas = P air + height difference

14. The Barometer High Pressure? Air would be pushing down harder. P gas = P air - height

15. Lecture Problem-Barometer

16. Standard Pressure ==> Units 760 mmHg 760 torrs 101300 Pascals 101.3 kPas 1 atm 14.7 lbs/in 2 Show dimensional analysis

17. Gas Law Problems: We have a problem with the gas molecule. Why is this a problem? 1) They show attraction! Cant in Gas Law Problems 1) They take up space!!! Cant in Gas Law Problems Its our Physics problem: Disregard air resistance How do you do that?

18. Real Gases 1) They do exist. 2) They can liquefy - condensation of vapor. 3) They dont follow gas laws.

19. Ideal Gases 1) They dont exist. 2) They cant liquiefy. 3) They follow the gas laws.

20. So when do gases behave ideally so we can use them in our gas laws? Where they show no attraction to each other: What conditions would that be?

21. So when do gases behave so we can use them in our gas laws? Ideally Where they show no attraction to each other: What conditions would that be? 1) Low pressures 2) High temperatures