Determination of sodium hypochlorite content in the anode solution used in chlor-alkali production
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This post was last edited by sunjl1981 on 2013-1-6 at 23:24. Dear forum members, the method I found in books for determining the sodium hypochlorite content in the anode solution is as follows: under acidic conditions, the sodium hypochlorite content = total effective chlorine (i.e., the sum of free chlorine and sodium hypochlorite) – free chlorine. The effective chlorine is determined using an acetic acid/k iodide/sodium thiosulfate/starch solution method, and the same method is used to measure free chlorine, except that no acetic acid is added. Since the anode solution is already acidic, I don’t think this method is suitable for measuring free chlorine. What are everyone’s thoughts on this issue? # ， ， &
Why isn’t anyone coming in to discuss this topic? ? I am looking forward to the advice from all the experts! !
Determination of sodium hypochlorite content in slightly saline water: In an acidic solution, free chlorine and sodium hypochlorite can oxidize iodide ions to iodine; the free iodine is then titrated using a standard sodium thiosulfate solution. The reaction equation is as follows: 2. Reagents and solutions: (1) 0.01N standard sodium thiosulfate solution; (2) 30% acetic acid solution; (3) 10% potassium iodide solution; (4) 1% starch solution. 3. Procedure for determination: Add 10 ml of 10% potassium iodide solution and 10 ml of 30% acetic acid solution to a 250 ml iodometric flask. Then quickly add 25 ml of the sample cooled to room temperature. Seal the flask and shake well; allow it to stand in the dark for 5 minutes. Titrate using the 0.01N standard sodium thiosulfate solution via a micropipette. The endpoint is reached when the light yellow color of the solution disappears completely. A blank test should also be conducted simultaneously. 4. Calculation: In the formula: – Volume of sodium thiosulfate standard solution used for determining total chlorine, in milliliters; – Volume of sodium thiosulfate standard solution used in the blank test, in milliliters; – Volume of sodium thiosulfate standard solution used for determining free chlorine, in milliliters. N – Equivalent concentration of sodium thiosulfate standard solution: 0.03723; – Grams per milliequivalent of sodium hypochlorite