1. Unit 9 Exam Review

2. Constants and Formulas Molar Volume : 22.4 L/mol Ideal Gas Constant:.0821 L*atm/mol *K Combined Gas Law: P 1 V 1 = P 2 V 2 n 1 T 1 n 2 T 2 Ideal Gas Law : PV = nRT Dalton’s Law of Partial Pressure: P total = P 1 + P 2 +…P n

3. Which of the following does not represent the behavior of an ideal gas? A gas where the particles are far apart A gas where the pressure is extremely high A gas where the temperature is extremely low A gas where the particles bounce off of one another

4. Which of the following describes the behavior of gases (in accordance with KMT)? A larger gas particle has more KE than a smaller gas particle at the same temp Gas particles bounce off of one another Gases exert force on their containers Gases slow down motion when temperature increases

5. Which formula will you need to solve the following: A sample of air occupies 2.0 L in an engine cylinder has a given pressure. How many liters must the cylinder be compressed to make the pressure 4 times its original pressure? P 1 V 1 = P 2 V 2 or Boyle’s Law

6. Which formula will you need to solve the following: A gas is heated so that it expands to three times it’s original size. How much does it need to be heated? V 1 /T 1 = V 2 /T 2 or Charles’ law

7. Which formula will you need to solve the following: Calculate the new pressure of a sample of oxygen occupying 35 mL at STP that gets released into a 1.0 L flask held at 273 K. P 1 V 1 = P 2 V 2 or Boyle’s Law

8. Which formula will you need to solve the following: A sample of carbon dioxide is trapped in a flask with sulfur dioxide. The flask is connected to a pressure sensor reading 140. kPa, and pressure of the sulfur dioxide is 60kPa. What is the pressure of the carbon dioxide? P Total = P 1(CO 2 ) + P 2(SO 2 ) Dalton’s Law of Partial Pressures

9. Which formula will you need to solve the following: How many degrees Celsius must a sample of ammonia gas in a rigid container be heated in order to double the pressure? P 1 /T 1 = P 2 /T 2 or Gay-Lussac’s law

10. Which formula will you need to solve the following: If a sample of gas at 1.00 atm and 251 K gets compressed into a 50.0 mL container, causing the temperature to be 311 K and the pressure to be 1.50 atm, what was its original volume? P 1 V 1 = P 2 V 2 or Combined Gas Law (n is constant) n 1 T 1 n 2 T 2

11. Solve: If a sample of gas at 1.00 atm and 251 K gets compressed into a 50.0 mL container, causing the temperature to be 311 K and the pressure to be 1.50 atm, what was its original volume? 60.5 mL

12. Which formula will you need to solve the following: How many moles of a gas occupy 400. mL at 760. torr and 50.0 K? PV = nRT Ideal Gas Law

13. Solve: How many moles of a gas occupy 400. mL at 760. torr and 50.0 K? R =.0821 L*atm/mol *K Convert torr to atm Convert ml to L.0974 mol

14. Oxygen gas at 35 o C in a sealed, rigid container has a pressure of 2.40 atm. If it is cooled to 5 o C, what will the new pressure be? 2.17 atm (rigid container = constant volume; sealed = constant mole)

15. No Calculator on the following questions #ISeeYou____________ » (insert name here)

16. The syringe volume was increased from 2.07 mL to 6.13 mL. If the original pressure was 1209 torr, what is the pressure when expanded? ~408 torr

17. If a sample of ammonia gas at STP has a volume of 12.1 L, what will its volume be when heated to 273.0 o C at constant pressure? 24.2 L

18. How many moles of gas are present if a sample of butane gas is held in a sealed 161.3 liter container at a temperature of 42.0 K and is under 625 torr of pressure? R = 62.4 torr*L/mol *K ~40 L

19. Sulfur trioxide (SO 3 ) gas is formed from sulfur dioxide (SO 2 ) and oxygen (O 2 ) gas. What volume of sulfur trioxide can be formed from.650 L of oxygen gas assuming the temperature and pressure are the same for both gases? 1.30L

20. If a gas in a rigid container has a pressure of 2.05 atm when the temperature is 310. K, what temperature does it need to be heated to in order to reach 4.01 atm of pressure? ~606 K

21. What will happen to the pressure of a gas at a constant temperature if its volume is decreased from 3.0 L to 1.0 L ? The pressure will triple

22. Which of these identical cylinders is under the greatest pressure? A B C D 1.00 mol 1.00 mol 0.5 mol 0.5 mol 250 K 300 K 250 K 300 K B (most mol with the highest temp)

23. Which of these identical cylinders is under the greatest pressure? A B C D 2.0 mol 1.0 mol 0.5 mol 0.5 mol 250 K 300 K 500 K 600 K A (most amount of moles/particles of gas)

24. 2 NaHCO 3(s)  1 Na 2 CO 3(s) + 1 H 2 O(g) + 1 CO 2 (g) If 6.00 moles of NaHCO 3 react as shown above, how many liters of CO 2 gas will be produced at STP? Convert mol NaHCO 3 to mol CO 2 Use molar volume because it’s at STP to convert to L CO 2 67.2 L

25. Convert L O 2 to L H 2 using the mole ratio 10.0 L

26. Convert L N 2 O to L NH 4 NO 3 with mole ratio because it’s at STP divide by 22.4L to convert to mol NH 4 NO 3 Multiply by formula mass (80.052) 0.357g

27. Gra ms Write a balanced equation for the combustion of methane (CH4) Convert L CH 4 to L H 2 O with mole ratio because it’s not at STP use PV=nRT to calculate mol of H 2 O Multiply by formula mass of water 9.74g H 2 O(g)