Regarding the analysis of sodium carbonate in the light brine from the tank?
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In the past month, the analysis results of the light brine from the electrolysis device in our workshop contain a certain amount of sodium carbonate. It was first discovered in the pre-processor, but I felt something was wrong later. Later, I contacted and analyzed the distribution tank, chemical tank, dechlorinated light brine, and outlet light brine and found that sodium carbonate has a certain amount of energy. ； I don’t know much about chlor-alkali analysis. Could you please analyze this situation and where does the problem occur?
The pH of the light brine coming out of the tank should be between 4 and 5. How come there is sodium carbonate? Is there something wrong with the analysis method? There are still other substances that interfere with the analysis, or the operator has errors in the titration technique, or the standard solution used for titration is not calibrated accurately, and there is a deviation in the calculation.
Indeed, it should be certain that there is an error in the analysis, and there is something wrong with the method or the standard solution.
The pH of the light brine coming out of the ion membrane tank is around 4. How could there be sodium carbonate? The poster doesn’t know what the content is. To titrate sodium carbonate, methyl orange is used as an indicator and hydrochloric acid is used for titration. If the content is very low, it is possible that alkali is added to the light brine at a later stage, and the alkali is brought in (the reaction between alkali and carbon dioxide in the air will produce a small amount of sodium carbonate). Otherwise, it can only be a problem with your analysis. No sodium carbonate has been analyzed in the light brine in our factory.
I just don't know what form carbonate exists in acidic conditions? I don’t understand analysis, please give me some advice!
There is something wrong with the eyes that see things, the vision is not accurate, and the illusion is
Because the 50ml sample taken was too large, the amount of indicator was insufficient, the titration was incomplete, and the titration end point was not accurately grasped due to operating techniques, resulting in the analysis results being too high for sodium carbonate and too low for sodium hydroxide. Suggestion 1. Check whether the indicator is neutral. 2. Use mixed indicators. 3. Operate carefully and accurately grasp the titration end point. 4. Add parallel samples to ensure that the error of sodium hydroxide is less than 0.01g/l; sodium carbonate is less than 0.04g/l.