No.4 Analysis of Commercial Aspirin Tablets
Aims
To To determine the mass of acetylsalicylic acid per tablet in a given commercial sample of aspirn (Brand name).
Introduction
Aspirn, which is chemically named as acetylsalicylic acid, when is hydrolyzed by excess sodium hydroxide solution, produces acetic acid and salicylic acid. The amount of excess sodium hydroxide solution can be found by back titration.
Procedure
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Standardisation of sodium hydroxide solution
25 cm3 ofApproximately 1M NaOH was pipetted into a 250 cm3 volumetric flask and made up to graduation mark with deionized water. 25 cm3 portion of this solution was titrated against standard 0.05M sulphuric acid with phenol red as indicator. The titration was repeated twice and the result was recorded in a table.