1. Yr 10 Chemistry
Dilutions

2. Starter

3. Objectives
To KNOW the meaning of dilution factor, serial dilution and the formula C1V1=C2V2
To BE ABLE TO calculate new concentrations when diluted.
To UNDERSTAND that when solutions are diluted, the moles of solute does not change.

4. Remember When we dilute solutions we are: CHANGING the SOLVENT.
The SOLUTE amount is UNCHANGED

5. C1 = n/V1 (the moles represents the solute)
Rearranging the equation
n = C1V (the volume represents the solvent)

6. When we change the volume (V1) of the solvent to V2:
The concentration changes (C2).
The moles of solute remain unchanged.
Therefore C1V1 = C2V2

7. If I have 340 cm3 of a 0.5 M NaBr solution, what will the concentration be if I add 560 cm3 more water to it?
C1 = 0.5 M
V1 = 340 cm3
C2 = ?
V2 = 560 cm3
C1V1 = C2V2
0.5 x = C2 x 0.560
0.17 = C2 x 0.560
C2 = M

8. Practice
If I dilute 250 mL of 0.10 M lithium acetate solution to a volume of 750 mL, what will the concentration of this solution be?

9. If I leave 750 mL of 0.50 M sodium chloride solution uncovered on a windowsill and 150 mL of the solvent evaporates, what will the new concentration of the sodium chloride solution be?
To what volume would I need to add water to the evaporated solution above, to get a solution with a concentration of 0.25 M?

10. Dilution Factor = Dilution Factor C1/C2 = Dilution Factor
The DILUTION FACTOR is how many times less concentrated is a new solution.
First concentration
Second Concentration
Dilution Factor =
C1/C2 = Dilution Factor

11. A 10M solution has been diluted to 2M solution what is the dilution factor?

12. You do a dilution by combining 100 ml  of 1M MgCl2 plus 700 ml unit volumes of RO water.  What is the  dilution factor, i.e, how many more times dilute is it than the original concentration? 

13. Serial Dilution
A serial dilution is simply a series of simple dilutions which amplifies the dilution factor quickly beginning with a small initial quantity.
Final dilution factor (DF) = DF1 * DF2 * DF3 etc.

14. Putting it All Together
A g sample of sodium chloride was weighed out and added to a mL volumetric flask.
What is the concentration of the sodium chloride solution?
This solution was diluted by a dilution factor of 2. This was done 10 times (that is taking half of the original solution and making it back up to 100ml in a new volumetric flask)
What is the new concentration?

15. A 12.50 ml sample was removed from the volumetric flask and transferred to a beaker.
How many moles of sodium chloride were transferred to the beaker?