1. Welcome Back! (11/27) Get ready for quiz! (25 minutes) Calculator
Periodic Table

2. Lab 6 – wrap up at end of class if needed
NO ONE came to mass their clean glassware???
Get your “correct” answer from me before you go today!
Remember: Lab due Wednesday before class to Google Drive (see handout for expectations)! Use your feedback from Lab 1!

3. Last Section of Chapter 1!
Gases = Ch 1.3 (pg 33-46)
Can Crush as a thinking tool…explain Friday?

4. UNDER PRESSURE A simulation for you…

5. Pressure = collisions with a container
Temperature = how fast the particles are moving
Units of pressure:
1 atmosphere =
760 torr or mmHg = psi = kPa

6. Avogadro’s Law (V and n)
Demo: what happens when more molecules are added?
V = constant * n
Ping pong balls, Balloons and adding more molecules = gets bigger

7. Avogadro’s Law meets stochiometry
Equal volumes of gas, when in the same conditions (T and P), contain an equal number of particles
Consider the equation: 2CO + O2  2CO2
When 40 cm3 of each CO and O2 are mixed, what volume of CO2 is produced?
How much of the excess reagent (in cm3) remains?
Most of a gas sample is empty space, so the identity of the gas doesn’t matter. Collisions = pressure, so if two samples have the same P at the same T, we assume the same n
Answer: 40 cm3 CO2 can be made, 20 cm3 of oxygen leftover

8. Practice Balance the following equation: C6H14 + O2  H2O + CO2
When 150 cm3 of hexane are mixed with cm3 of oxygen, what volume of CO2 is produced?
Volume CO2 = 470 cm3

9. Boyle’s Law (Pressure and Volume)
Demo!
P = constant * V
If you have an original gas sample with a volume of 5.0 L and a pressure of 1.2 atm, what is the new volume if the pressure is decreased to 0.75 atm?
Vacuum chamber and balloon! 8.0 L

10. Syringe Time! Where are the molecules? How are they behaving?
Draw pictures!
Calculate the pressure of the compressed syringe assuming today’s pressure is 0.95 atm.

11. Charles’ Law (Volume and T)
Demo I wish!
V = constant * T
This is a tough one! If we want to keep Pressure constant, the temperature actually has to go DOWN so that there are the same number of collisions as before.

12. Amonton’s Law (Pressure and Temperature)
P = constant * T
Hot water with balloon or video of liquid nitrogen balloon? Or just ping pong balls again

13. Temperature Conversion
Important!! You MUST convert Celsius to Kelvin!
What is the conversion?
K = C + 273

14. Apply the laws!
If a container can only swell to 7.2 L before it breaks, and a sample of gas is inside at C is 2.5L, what temperature of gas will cause the container to break?
600 Celsius

15. Review: When pressure increases, volume___________
When temperature increases, volume________
When number of particles increases, volume_______
Decreases, increases, increases

16. Relationships Practice
If the volume of a container is cut in half, what happens to:
The Pressure (if T and n are constant)?
The Temperature (if P and n are constant)?
P = x2, T = 1/2

17. Ideal Gas Law Derivation!
Put it all together!
PV = nRT

18. Homework Day 7
Lab 6 Due before next class to Google Docs – make it fantastic!
TEXTBOOK: Read pages and take notes before next class!
Make sure you have your laptop for class W!