DETERMINATION OF MIXTURE CONTENTS The mixture levels were determined on samples of vitamin C and salicylic acid. In this case, acetosal and vitamin C are acidic substances, so their levels can be determined using the alkalimetric method. This alkalimetric method will obtain the concentration of mixed acid samples. Meanwhile, according to the Indonesian Pharmacopoeia, vitamin C is determined using the iodimetric method. After obtaining the vitamin C level, the salicylic acid level/mole can be calculated by calculating the difference from the total sample level/mole minus the vitamin C sample level. Implementation of Practicum a. Tools and materials Burette, volume pipette, measuring flask, analytical balance, funnel, beaker, Erlenmeyer, spray bottle, bulb, measuring cup, Na2S2O3 0.1N, I2 0.1N, KIO3, starch indicator, Potassium Iodide, Sulfuric Acid 2 N, NaOH 0 ,1N, Kaliun Hydrogen Pthalate, distilled water. b. Work procedures 1. Preparation of 0.1 N NaOH Titer Solution Dissolve 4.0 grams of NaOH in CO-free water2sufficient to 1000.0 ml. 2. Making Phenolphthalein Indicator Dissolve 0.1 g of indicator in 100 ml of 95% ethanol (v/v). 3. Standardization of the NaOH titer solution. Carefully weigh 100 mg Erlemeyer, add 20 ml of CO-free water2, stir until dissolved. Give 1-2 drops of penolphthalein indicator. Titrate with NaOH until a light pink color appears. Perform triple titration, calculate the concentration of the titer solution. 4. Determination of Concentration Carefully weigh 250 mg of sample, add ethanol, place in Erlemeyer, add 20 ml of CO free water2, stir until dissolved. Give 1-2 drops of penolphthalein indicator. Titrate with NaOH until a light pink color appears. Perform triple titration, calculate sample concentration. Potassium Biphthalate, put in Iodimetry Procedure 1. Preparation of titer I solution20.1 N Dissolve 18 grams of KI in 30 ml of water in a closed flask. Weighs approximately 12.69 grams I2in a watch glass, add little by little to the KI solution. Close the flask and shake until the Iodine dissolves. Leave the solution at room temperature and add water to make 1000.0 ml. 2. Preparation of Na solution 2S2O30.1 N Weigh approximately 26 grams of sodium thiosulfate and 200.0 mg of sodium carbonate in enough fresh carbon dioxide-free water to make 1000.0 ml. 3. Making Kanji Indicators 10 grams of amylum in 100 ml of hot water 4. Standardization of Na2S2O3 Carefully weigh 100 mg KIO3, add 300 mg KI and 10 ml dilute sulfuric acid. Titrate with Na2S2O3until light yellow. Add the starch indicator and titrate again until a color change occurs. Do a triple. Calculate the normality of Na2S2O3. 5. Standardization of titer I solution2with Na2S2O3 Pipette 15.0 ml of Na solution2S2O3which has been standardized, put it in an Erlemeyer, add starch indicator, titrate with solution I2 until it turns blue. Do a triple. Calculate normality I2. 6. Determination of levels Carefully weigh 150 mg of sample, place in a 100 ml Erlemeyer, add 5 ml of dilute sulfuric acid solution, titrate with I20.1 N with amylum indicator until blue. Perform triple titration, determine sample concentration.