1. Unit 3, Lesson 14: Dilutions

2. Dilution
If I add water to a solution, I make it more dilute. This is called dilution.
When I do this, the amount of solute (in mol) does not change.
Thus mol1 = mol2.
Since moles = molarity x volume, M1V1 = M2V2.
We can use this equation to find the new concentration after a dilution.

3. Examples
If mL of M NaCl is added to mL of water, what is the resulting [NaCl] in the solution?
If mL of M NaCl is added to mL of M NaCl, what is the resulting [NaCl] in the solution?
Reminder: for #2, find [NaCl] from each dilution, then add them together.
10 min

4. Brain Break!

5. Now You Try!
What volume of 6.00 M HCl is used in making up 2.00 L of M HCl?
A student mixes mL of water with 25.0 mL of a NaCl solution having an unknown concentration. If the diluted solution has [NaCl] = M, what is the molarity of the original NaCl solution?
20 min

6. Practice, Practice, Practice!
Homework: Pg. 102 #78-94 even numbers.
Extra practice: Pg. 103 # – these are good practice problems to prepare you for the unit test!
10 min