Catalyst Calculators today! 1. The equation for Boyle’s Law is P1V1 = P2V2. Use this law to solve the following problem: A 12.5 L container of neon had a pressure change from 1.25 atm to 3.5 atm. What is the new volume? 2. Do pressure and volume have a direct or indirect relationship? 3. Sophomores/seniors only: A balloon has a volume of 253.2 mL at 356 K. The volume of the balloon is decreased to 165.4 mL. Determine the new temperature.

Updates Juniors: check your progress report for missing packets (Weeks 8 and 9) and the missing take-home quiz Turn these in today! Quiz on Friday Boyle’s Law, Charles’ Law, Ideal Gas Law Packet will be collected Friday– ALL homework must be completed, including for juniors Check the board for missing tests/quizzes or incompletes Come to 8th period Thursday or Friday

Today’s Agenda Catalyst Review Charles’ and Boyle’s Laws 5 min Catalyst 20 min Review Charles’ and Boyle’s Laws 25 min The Ideal Gas Law Exit Slip

Name it: Boyle’s Law Boyle’s Law says that pressure is indirectly proportional to volume. As P increases, V decreases and vice versa Equation: Final Volume Initial Pressure Initial Volume Final Pressure

Example A gas occupies 1.56 L at 1 atm. What will the volume be if the pressure becomes 3 atm?

New Law Charles’ Law demonstration What will happen to the volume of a gas if the temperature is increased/decreased?

Charles’ Law Charles’ Law says that gases tend to expand (increase in volume) when heated (increase in temperature). This is a direct relationship. The Equation V1 = V2 T1 T2 V = volume T = temperature in KELVIN!!!! (convert if it is in Celsius--- add 273)

Solving Charles’ Law Problems On hot days, you may have noticed that potato chip bags seem to “inflate”, even though they have not been opened. If I have a 0.250 L bag at a temperature of 292 K , and I leave it in my car which has a temperature of 333 K, what will the new volume of the bag be? SOLUTION : GUESS

RECAP! Pressure = atmospheres (atm) Volume = liters (L) Temperature = Kelvin (K) Boyle’s Law is for pressure and volume (indirect relationship) Charles’ Law is for temperature and volume (direct relationship)

Extension For each of the following, tell whether the two things have a direct or indirect relationship. Remember- THINK, don’t guess! (We haven’t gone over some of these yet!) 1. Pressure and volume 2. Temperature and volume 3. Pressure and temperature 4. Number of molecules and volume 5. Speed of the molecules and temperature

Pressure and Temperature http://www.youtube.com/watch?v=4qe1Ueifekg

Today’s Agenda Catalyst Review Charles’ and Boyle’s Laws 5 min Catalyst 20 min Review Charles’ and Boyle’s Laws 25 min The Ideal Gas Law Exit Slip

OBJECTIVES Scholars will derive the ideal gas law Scholars will define R as a constant number Scholars will calculate problems using the ideal gas law

IDEAL GAS LAW We have two new variables to deal with: n and R. n = the number of moles of gas R is a “constant” number = 0.08206 This means that R is ALWAYS that same number The ideal gas law is PV=nRT

IDEAL GAS LAW EXAMPLE A sample of gas at a pressure of 3 atm occupies a volume of 2.0 L at 27° C. How many moles of the gas are there? GUESS METHOD!

IDEAL GAS LAW EXAMPLE 2 At what temperature does a 5 mole sample of gas at a pressure of 1.5 atm occupy a volume of 2.5 L. GUESS METHOD!

Today’s Agenda Catalyst Ideal Gas Law Equation Practice Exit Slip 5 min Catalyst 25 min Ideal Gas Law Equation 15 min Practice Exit Slip

Practice 1. If I have 4 moles of a gas at a pressure of 5.6 atm and a volume of 12 liters, what is the temperature? 2. If I have an unknown quantity of gas at a pressure of 1.2 atm, a volume of 31 liters, and a temperature of 360 K, how many moles of gas do I have? 3. I contain 3 moles of gas in a container with a volume of 60 liters and at a temperature of 400 K, what is the pressure inside the container? 4. If I have 7.7 moles of gas at a pressure of 0.09 atm and at a temperature of 329 K, what is the volume of the container that the gas is in? 5. If I have 17 moles of gas at a temperature of 340 K, and a volume of 88.89 liters, what is the pressure of the gas? If I have an unknown quantity of gas at a pressure of 0.5 atm, a volume of 25 liters, and a temperature of 300 K, how many moles of gas do I have? 21 moles of gas held at a pressure of 78 atm and a temperature of 900 K, what is the volume of the gas? If I have 1.9 moles of gas held at a pressure of 5 atm and in a container with a volume of 50 liters, what is the temperature of the gas? If I have 2.4 moles of gas held at a temperature of 370 K and in a container with a volume of 45 liters, what is the pressure of the gas? If I have an unknown quantity of gas held at a temperature of 1195 K in a container with a volume of 25 liters and a pressure of 560 atm, how many moles of gas do I have? If I have 0.275 moles of gas at a temperature of 75 K and a pressure of 1.75 atmospheres, what is the volume of the gas?  If I have 72 liters of gas held at a pressure of 3.4 atm and a temperature of 225 K, how many moles of gas do I have?

Today’s Agenda Catalyst Ideal Gas Law Equation Practice Exit Slip 5 min Catalyst 25 min Ideal Gas Law Equation 15 min Practice Exit Slip

Exit Slip 1. According to the ideal gas law, as the number of molecules goes up, the pressure will ___________. 2. According to Charles’ Law, as the temperature goes up, the volume will go ______________. 3. According to Boyle’s Law, as volume goes up, pressure will go ______________. 4. If I have an unknown quantity of gas at a pressure of 0.5 atm, a volume of 25 liters, and a temperature of 300 K, how many moles of gas do I have?