1. Unit 9 Acc Chem Review Note: You must memorize STP and the gas laws!!

2. The Kinetic Molecular Theory states that gas particles are ____________ and are separated from one another by lots of _________ space. Particles are in constant, rapid and _________ motion. The particles collide with each other and the sides of the container – this is what causes ______________. During these collisions, no ___________ is lost. The higher the _______________, the faster the particles move. small empty random Pressure energy temperature

3. List 4 properties of gases. 1. 2. 3. 4. Low Density Conform to container size Can diffuse & effuse Can be compressed

4. Explain why gases are compressible, have a low density and can diffuse: Compressible, because of large amount of empty space Low density, due to lots of empty space Diffuse, due to random, rapid particle motion

5. 4. A _______________ is used to measure atmospheric pressure and a __________ is used to measure gas pressure within a container. barometer manometer

6. 5. What 4 variables are used to describe gases? What units do we use for these variables? 1. 2. 3. 4. Pressure - atm Volume - L Amount of gas - moles Temperature - k

7. 6. When pressure doubles on a fixed sample of gas and the temperature remains constant, what will happen to the volume? ____________(Be specific) Reduce by 1/2

8. 7. When the temperature of a fixed sample of gas triples and the pressure remains constant, what happens to the volume? ____________________ (be specific) Volume triples

9. 8. If the pressure on a fixed amount of gas in a rigid container is reduced by half, what had to happen to the temperature of that gas? _________________ (be specific) Increase by 2

10. 9. State Dalton’s law of partial pressures in words & write the equation. Total pressure of gas sample is equal to the sum of all gases in the sample ( P t = P 1 + P 2 + P 3 …)

11. 10.What does STP stand for? 11. Standard temperature is ________  C or _________ K. 12. Standard pressure is _________ atm, __________ kPa or _________ mm Hg. Standard Temperature Pressure 0 273 1 atm 101.3 760

12. 13. State Avogadro’s Principle. 14. One mole of any gas at STP occupies _________ L. This is called the ___________ volume. 1 Mol of gas at STP is 22.4L. molar 22.4

13. 15. When solving gas law problems, temperature must always be expressed in _____________. Kelvin

14. 16. At 100.0 kPa a balloon has a volume of 1.50 L. What will the volume be at a pressure of 3.25 atm?

15. 17. A 1.25 L container holds 17.5 g oxygen gas (O2) of gas at 275 K. What is the pressure?

16. 18. A balloon as a volume of 15.4 L at STP. What would its volume be at 1.25 atm when the temperature decreases 55K?

17. 19. A gas is generated at 20.0  C and 2.100 atm. Under a constant volume, the gas is heated to a pressure of 3.13 atm. What is the new temperature?

18. 20. If a gas has a volume of 25.5 L at a temperature of 95.0  C, what is the temperature if the volume is decreased to 5.0 L?

19. 21. If 2.65 mole of methane gas occupy 15.0 L at 1.50 atm, what is the temperature of the gas in K? and in Celsius?

20. 22. A gas is collected by water displacement. If the total pressure is 103.67 kPa at and the pressure due to the water vapor is 1.72 kPa, what is the pressure of the dry gas?

21. 23. What is the mass of 14.50 L of oxygen gas at STP?

22. 24. How many grams of hydrogen gas are needed to react with 25.50 L of oxygen gas at 2.50 atm and 23.95  C. 2 H 2 + O 2  2 H 2 O

23. 25. Determine what state of matter is present in sections 1-3 SOLID LIQUID GAS

24. 26. What do points B, D, E, F represent? B = triple point D = critical point E = normal freezing point/normal melting point F = normal boiling point/normal condensing point

25. 27. At a temperature of 100  C, if the pressure drops from 200 kPa to 50 kPa, what phase change occurs? vaporization

26. 28. At what temperature and pressure will all 3 states of matter exist for this substance? 0.01  C and 0.611 kPa

27. 29. At a pressure of 101.3 kPa, if the temperature increases from -60  C to 60  C, what phase change occurs? melting