1. Titration Pre-lab

2. What is titration?
Method to determine the concentration of one solution based on its rxn with a known solution (titration standard)
It determines the unknown molarity of a given solution

3. The Process You have the following
50 ml Unknown solution (acid or base)
Known solution (acid or base)
If you have an unknown acid you will need the known base and vice versa
An indicator (phenolphthalein or methyl orange) to show a change in pH

4. The process The lab process:
Pour 1/3 of the unknown (~16.7 ml) into the Erlenmeyer flask. Be sure to record the exact amount in your data table
If you have an unknown acid put the flask underneath the base buret.

5. The Process Add 3 drops of indicator
Phenolphthalein is colorless in acids and pink in bases at about a pH 8.2
Methyl orange is red in acids and turns yellow at about 4.4

6. The Process
Check your buret of the standard you are using. Be sure it is the opposite of the unknown, and that it is reasonably full. Be sure there are no air bubbles in the tip
Take the initial reading of the buret and record it. Read to the nearest 100th of a ml

9. The Process Have 1 person constantly swirling the flask
The other person should slowly add small amounts of standard solution
When the unknown solution appears to be close to changing colors slow down and add 1 drop at a time until the color stays (end point)

10. The Process
If the color of the end point is a deep color you added too much. The end point should be a light, barely a change in color.
Record the final buret reading and the color in the data table

11. The Process
Rinse the flask with tap water thoroughly and repeat this 2 more times.
Thoroughly clean and dry all equipment. Leave unused standard solution in the burets

12. The Calculations
Calculate the molarity for each trial using M1V1 = M2V2
M1 = molarity of acid
V1 = volume of acid
M2 = molarity of base
V2 = volume of base
Find the average of the 3 trials