Analysis of the mass of acetylsalicylic acid (aspirin) in an Aspirin Tablet.

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Standardization of dilute sulphuric acid

1. 1.32g of the sodium carbonate was weighted accurately in a beaker.

2. 120cm3 of deionised water was added to the beaker containing sodium carbonate.

3. The mixture was stirred gently to let the sodium carbonate to dissolve.

4. The solution was poured into a 250cm3 volumetric flask.

5. The beaker was washed out with further small quantities of water.

6. All the washings were poured into the 250cm3 volumetric flask to ensure no solution was left on the wall of the beaker.

7. Water was added into the conical flask until the mark was made up by a wash bottle.

8. The solution was shaked well.

9. 25cm3 of sodium carbonate solution was pipetted out and ran into a conical flask.

10. Two to three drops of methyl orange indicator solution was added into the conical flask..

11. A burette was filled with the sulphuric acid of unknown concentration.

12. The flask was swirled during the addition of dilute sulphuric acid.

13. Adding of diluted sulphuric acid was stopped when the color of the solution changed from yellow to pink.

14. Step 9 to step 13 was repeated twice in order to get a more accurate result.

Determination of acetylsalicylic acid in aspirin tablets/

1. Three tablets were weighted accurately.

2. The tablets were putted into a 250cm3.

3. 25cm3 of 1.0M sodium hydroxide was added into the conical flask by a pipette.

4. 25cm3 of deionised water was added into the flask to dilute the solution.

5. The flask was warmed over a tripod and gauze for ten minutes.

6. The reaction mixture was cooled and transferred with washings to a 250 cm3 volumetric flask.

7. 25cm3 of the solution was titrated with the standardized sulphuric acid, using phenolphthalein as...