1. OB: You will now become a gas master Review of all gas math. Get a reference table and a calculator, here we go. All questions from old regents exams

2. June 2011 15 According to the kinetic molecular theory, the particles of an ideal gas (1) have no potential energy (2) have strong intermolecular forces (3) are arranged in a regular, repeated geometric pattern (4) are separated by great distances, compared to their size 43 Which temperature change would cause a sample of an ideal gas to double in volume while the pressure is held constant? (1) from 400. K to 200. K (2) from 200. K to 400. K (3) from 400.°C to 200.°C (4) from 200.°C to 400.°C

3. June 2011 15 According to the kinetic molecular theory, the particles of an ideal gas (1) have no potential energy (2) have strong intermolecular forces (3) are arranged in a regular, repeated geometric pattern (4) are separated by great distances, compared to their size 43 Which temperature change would cause a sample of an ideal gas to double in volume while the pressure is held constant? (1) from 400. K to 200. K (2) from 200. K to 400. K (3) from 400.°C to 200.°C (4) from 200.°C to 400.°C

4. January 2011 19 Under which conditions of temperature and pressure does carbon dioxide gas behave most like an ideal gas? (1) low temperature + low pressure (2) low temperature + high pressure (3) high temperature + low pressure (4) high temperature + high pressure August 2010 18 Which gas sample at STP has the same total number of molecules as 2.0 liters of CO 2(G) at STP? (1) 5.0 L of CO 2(G) (3) 3.0 L of H 2 S (G) (2) 2.0 L of Cl 2(G) (4) 6.0 L of He (G)

5. January 2011 19 Under which conditions of temperature and pressure does carbon dioxide gas behave most like an ideal gas? (1) low temperature and low pressure (2) low temperature and high pressure (3) high temperature and low pressure (4) high temperature and high pressure August 2010 18 Which gas sample at STP has the same total number of molecules as 2.0 liters of CO 2(G) at STP? (1) 5.0 L of CO 2(G) (3) 3.0 L of H 2 S (G) (2) 2.0 L of Cl 2(G) (4) 6.0 L of He (G)

6. June 2010 41 A sample of gas confined in a cylinder with a movable piston is kept at constant pressure. The volume of the gas doubles when the temperature of the gas is changed from (1) 400. K to 200. K (3) 400.°C to 200.°C (2) 200. K to 400. K (4) 200.°C to 400.°C January 2010 19 Under which conditions of temperature and pressure would a 1-liter sample of a real gas behave most like an ideal gas? (1) 100 K and 0.1 atm (2) 100 K and 10 atm (3) 500 K and 0.1 atm (4) 500 K and 10 atm

7. June 2010 41 A sample of gas confined in a cylinder with a movable piston is kept at constant pressure. The volume of the gas doubles when the temperature of the gas is changed from (1) 400. K to 200. K (3) 400.°C to 200.°C (2) 200. K to 400. K (4) 200.°C to 400.°C January 2010 19 Under which conditions of temperature and pressure would a 1-liter sample of a real gas behave most like an ideal gas? (1) 100 K and 0.1 atm (2) 100 K and 10 atm (3) 500 K and 0.1 atm (4) 500 K and 10 atm

8. At constant pressure, a 12.0 liter sample of CO 2 gas is at 24.0°C. If the sample is cooled to -15.0°C, what’s the new volume of gas?

9. First dump the centigrade, convert to Kelvin. Write your formula, omitting pressure (it’s a constant). Fill in the formula, do the math. V1T1V1T1 V2T2V2T2 = 12.0 L 297 K V 2 268 K = (12.0L)(268 K) = (V 2 )(297 K) 10.8 L = V 2

10. A weather balloon has been filled with helium to a volume of 65.5 liters, at 1.50 atm, and the gas temperature is 295 K. At a height of twelve hundred meters, the balloon cools to 265 K, and the volume drops to 62.0 Liters. What is the pressure in this balloon under these new conditions?

11. P1V1T1P1V1T1 P2V2T2P2V2T2 = (1.50 atm)(65.5 L) 295 K (P 2 )(62.0 L) 265 K = (1.50 atm)(65.5 L)(265 K) = (P 2 )(62.0 L)(295 K) 1.42 atm = P 2

12. When we celebrate gases. Here’s how to do well: 1 You will be able to write out the KMT and explain each of the parts. 2 You will be able to draw 3 graphs, showing the relationships between: Pressure + Volume, pressure + temperature, volume + temperature. 3 You will be able to state and explain Avogadro’s Hypothesis 4 You will be able to calculate any pressure conversions 5 You will be able to calculate any type of combined gas law problems 6 You will describe the difference between real and ideal gases 7 You will have read the BASICS twice. The celebration will be short, sweet, and hopefully for you, fairly low pressure event (haha).