1. FINDING THE CONCENTRATION OF ASPIRIN THROUGH TITRATION
Nadia W
Aim: To find the concentration of aspirin in an aspirin tablet through the process
of titration.
Theory Background: Aspirin is an acid that is also known as acetyl salicylic
acid. It is generally used to relieve pain without having someone having to lose
consciousness or having to have an anaesthetic, it is mostly used on mild aches
and pains.
Materials:
1. 0.1M NaOH
2. Burette
3. Ethanol
4. Mortar & Pestle
5. Phenolphthalein Indicator
6. Stirrer
7. Weighing scales & boats
8. 150ml Beaker
9. Erlenmeyer flask
10. 10ml Pipette
11. 25ml Pipette
12. Rubber Pump
13. Clamp Stand
14. Distilled Water
15. Dropper
Procedure:
1. Grind 3 tablets of one brand of aspiring by using a mortar and pestle.
2. Take 1g of the powdered aspirin and place it in a 150ml beaker.
3. Add a 20ml portion of ethanol to the beaker and stir.
4. Add 50ml of distilled water to the beaker.
5. Take 10ml of the solution and put it in a flask.

2. 6. Put 3 drops of the phenolphthalein indicator in your flask.
7. Fill the burette with 0.1M NaOH.
8. Begin titrating. Add the NaOH, making note of when the colour change
occurs.
9. Repeat steps 2-7 for the remaining tablets and repeat steps 1-7 for the
other brand of aspirin.
Data:
First Trial Second Trial Third Trial Average
First Brand 4.3ml 4.7ml 4.7ml 4.6ml
Second Brand 4.6ml 4.2ml 4.8ml 4.5ml
First Brand
V1 M1 = V2 M2
10 x M1 = 4.6 x 0.1
M1 = 0.046M
Second Brand
V1 M1 = V2 M2
10 x M1 = 4.5 x 0.1
M1 = 0.045M
Conclusion: According to this experiment both brands have almost similar
concentrations of aspirin. The first brand has 0.046M Aspirin while the
second brand has 0.045M Aspirin. The real concentration might be of equal
value if there weren’t any minor experimental errors.