Science Starter (Week 13, Day 1, 4/25/16) Grab a calculator! Place HW on desk Science Starter (Week 13, Day 1, 4/25/16) If I have a sample of gas that has an initial temperature of 273K and ends with a temperature of 280K and a pressure of 57 psi, what was the initial pressure (in atm)? Explain in 2 sentences how a alcohol thermometer works. Which of the following statements is not true? Gas particles are constantly moving. Gas particles transfer motion and energy. Pressure is the force between gas particles colliding with each other.

Objective SWBAT calculate problems using the Ideal Gas Law SWBAT differentiate between problems that require the Ideal Gas Law and the Combined Gas Law

Agenda Science Starter Notes Exit Ticket Ideal Gas Law When to Use Which Practice Exit Ticket

Unit 6: Gas Laws The Ideal Gas Law

PV = nRT Notes: Ideal Gas Law P = pressure (atm) V = volume (L) “piv nert” This equation is used to predict any of these variables when the others are held constant. P = pressure (atm) V = volume (L) n = number of particles (moles) T = temperature (KELVIN!) R = gas constant - 0.0821 L atm mole K

When to Use Which…. Combined Gas Law Ideal Gas Law 2 pressures, 2 temperatures, 2 volumes When things are changing There is an action verb Things are held constant You see the words “moles” or “grams”/“mass”

Example The temperature inside my refrigerator is about 40 Celsius. If I place a balloon in my fridge that initially has a temperature of 220 C and a volume of 0.5 liters, what will be the volume of the balloon when it is fully cooled by my refrigerator?   Are you changing pressure, volume, temperature, or # of particles? Ideal or Combined? Solve.  

Example If I have 4 moles of a gas at a pressure of 5.6 atm and a volume of 12 L, what is the temperature? Are you changing pressure, volume, temperature, or # of particles? Ideal or Combined? Solve.

Flash! 1.0 L of a gas at 1 atm is compressed to .473L. What is the new pressure of the gas? Are you changing pressure, volume, temperature, or # of particles? Ideal or Combined? Solve.

Example Standard temperature is 0.00°C and standard pressure is 1.00 atm. Calculate how much volume 1.00 mole of gas occupies at STP.

Online Practice Sign into your laptop and go to my website Mrhoutzscience.weebly.com Scroll down to Chem (quick links!) Choose one of the links to follow and complete as many questions as possible (I will check at with 15 minutes left) If you complete all 10 show me for a full grade!

Flash! .89 moles of a colorless gas occupy a volume of 84.1 L and a pressure of 3.6 atm. What is the temperature of the gas?

Flash! If I have 80 g of carbon dioxide at a pressure of 1.6 atm and a volume of 6 L, what is the temperature? Are you changing pressure, volume, temperature, or # of particles? Ideal or Combined?

Flash! If I have an unknown quantity of gas held at a temperature of 1195 K in a container with a volume of 2.5 liters and a pressure of 760 torr, how many moles of gas do I have? Are you changing pressure, volume, temperature, or # of particles? Ideal or Combined?

Examples Nitrogen gas under a pressure of 1420 torr and at a temperature of 293 K occupies a .050 L container. How many grams of gas are in the container? R = gas constant - 0.0821 L atm K*mole

Exit Ticket

Exit Ticket If I have an unknown quantity of oxygen gas held at a temperature of 1195 K in a container with a volume of 2500 mL and a pressure of 560 atm, how many grams do I have? If I have a 50 L sample of gas that is compressed to 25 L and 35 psi, what was the initial pressure?