1. Warm-up I have an unknown volume of gas held at a temperature of 115 K in a container with a pressure of 60 atm. If by increasing the temperature to 225 K and decreasing the pressure to 30 atm causes the volume of the gas to be 29 liters, how many liters of gas did I start with?

2. The Ideal Gas Law Unit 8, Day 7 Kimrey 4 December 2012

3. A Bit More About Gases Remember gases are really tiny particles bouncing off of everything. These collisions are perfectly elastic. Meaning that no energy is lost as they collide. It’s because of this that the combined gas law works (P 1 V 1 /T 1 = P 2 V 2 /T 2 ).

4. Adding more gas So what happens if we add more of a gas? This can be accounted for by the ideal gas law.

5. Ideal Gas Law PV=nRT P= Pressure V= Volume n= moles R= gas constant T= Temperature

6. Units Temperature must be in Kelvin. Volume must be in liters (Remember: King Henry Died by drinking chocolate milk) Pressure can be in atm, mmHg, or kPa BUT you must use the appropriate R for whatever units of pressure you have. R is a constant and can be: (three options are found on the reference tables)

7. Converting to Kelvin Temperature can also be measured in a unit known as Kelvin. ▫Degrees Celsius plus 273 = Temperature in Kelvin ▫You don’t have to remember this! The reference tables show that 0 °C is the same as 273K 45°C is what in Kelvin? 5°C is what in Kelvin?

8. Example How many moles of a gas at 100°C does it take to fill a 1.00L flask to a pressure of 1.50 atm?

9. Example 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?

10. Example If I contain 3 moles of gas in a container with a volume of 60 liters and at a temperature of 400 K, how many atmospheres of pressure are inside the container?

11. Example If I have an unknown quantity of N 2 held at a temperature of 1195 K in a container with a volume of 25 liters and a pressure of 560 atm, how many grams of N 2 do I have?

12. Warm-up If I have an unknown quantity of N 2 held at a temperature of 1195 K in a container with a volume of 25 liters and a pressure of 560 atm, how many grams of N 2 do I have?

13. Stoichiometry!! Unit 8, Day 7 Kimrey 4 December 2012

14. Molar Volume 1 mole = 22.4 L of a gas at STP STP = 0°C and 1 atm

15. Examples How many liters of Nitrogen gas are there in 4.56 moles? How many liters of fluorine are there in 56.7 grams?

16. Stoichiometry…Again! N 2 + H 2  NH 3 64.0 L of nitrogen will produce how many liters of ammonia (at STP)? Don’t forget to balance!!!

17. Mole - Volume 2H 2 + O 2  2H 2 O How many liters of water will be produced from 15 moles of oxygen?

18. Mass - Volume 2H 2 + O 2  2H 2 O How many liters of water will be produced from 100 grams of Hydrogen gas if Oxygen gas is in excess?

19. STP Standard Temperature and Pressure 1 atm and 0 °C

20. Example In a laboratory experiment, 85.3 moles of a gas are collected at 24 °C and 733 mm Hg pressure. Find the volume at STP.

21. Not at STP… Use the ideal gas law to determine volume Then use that volume to complete the stoichiometry

22. Example Na 3 PO 4 + 3 KOH  3 NaOH + K 3 PO 4 If you have 25 moles of KOH at 175 K and 3.4 atm, how many liters of K 3 PO 4 are produced?

23. Example C 3 H 6 O + 4 O 2  3 CO 2 + 3 H 2 O At 823 mmHg and 329 K, 135 moles of oxygen are mixed with excess C 3 H 6 O. How many liters of water are produced?