Calibration: Weigh accurately 0.1500 ~ 0.2000gNa polymer 2 C 2 O 4 reference material were placed i

Wind Qing Yang V
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According to acid-base neutralization reaction, determination of the sum of sulfuric acid and oxalic acid, total titratable acidity using the acid-base titration, the titration agent used standard NaOH solution. Sulfuric acid pKb1 of 12.01 (pK a1 =?), Oxalic acid p is 9.81, can phenolphthalein (pH range 8.2-10.0) as an indicator when the solution polymer from colorless to pink when the endpoint is reached.
5. Phenolphthalein: 2g / L ethanol solution (2) concentration of oxalic acid titration: Each 25mL, parallel titration three (four).
Calibration: Weigh accurately 0.1500 ~ 0.2000gNa polymer 2 C 2 O 4 reference material were placed in three 250mL conical flask, add 60mL water to dissolve, add 15mL H 2 SO 4 (1 +5), a water bath heated to 75 ~ 85 , hot titration with KMnO 4. Slow start of the titration until the solution to generate a Mn 2 + speed can be accelerated after the titration until the solution presents reddish and continued half a minute does not fade is the end. Write down V KMnO 4
Where 134 is ..., 2/5 for the ......
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