1. Warm-up (Sept 19) Did you share lab 1 with me? I hope so!
How many liters of solution could you make if you used grams CaCl2 * 2H2O and wanted to make molar solution?

2. Hydrate lab DBQs – can we answer these questions?
A practice question for you!

3. Lab #2 Calculations
In your lab book, some further calculations from part 1:
What is your REAL concentration of your solution (based on your actual mass of salt?)
What is the concentration of Cu2+ ions in solution?
What is the concentration of NO3- ions in solution?

4. Lab #2 Part 2 - Dilution from a stock solution

5. Lab 2 – Gather materials and take a seat
Get out:
Goggles
50 mL beaker
50 mL volumetric flask
10 mL graduated glass pipette
Green pipette tool (same drawer as pipettes)
Distilled water bottle (make sure it’s full)

6. Lab #2 Part 2
Now, take 9.00 mL out of your flask using a volumetric pipette and transfer to a 50 mL volumetric flask and dilute to the mL line with water.
Make sure you are very exact with your mL pipette.
Calculate the new molarity of the solution.
You know how many moles are in there, and how much total solution, so THINK!
CLEAN UP: down the drain and wash flasks
20 min

7. What happens to the M when we dilute it with water?
Which variables stay the same?
Which variables change?
The moles in the before and after solution are equal. The volumes and M values change as a result.
Equation: M1V1 = M2V2

8. A very important equation!
M1V1=M2V2

9. Practice…
When 75.0 mL of water is added to mL of a 1.25 M solution of Na2CO3, what is the new molarity?
0.714 M

10. Practice…
Explain in detail how you would prepare a mL of a 1.75 M solution of H2SO4 from concentrated H2SO4 (18.0 M):
What is the [H+] in the final solution?
24.3 mL stock into a mL volumetric flask, fill to line carefully with water.

11. Practice Problems
How much water would need to be added to reduce the molarity of mL of 15.0 M HNO3 to 3.5 M?
330 mL

12. Peer Edit an old AP Chem lab!
Hydrate lab from last year – use the rubric

13. Homework Day 6
SHORT Webassign 2 (just for practice with a couple dilution problems)
Due before class Th
Finish Peer Editing the Lab before class Thursday
Lab 3 Tomorrow – don’t forget shoes and books!