Haiyou, please help answer questions about sodium hypochlorite
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In industry, sodium hypochlorite is used to maintain the pH at around neutral. I would like to ask whether sodium hypochlorite inside the tower decomposes into sodium hydroxide? I’ve looked up information on the reactions involving sodium hypochlorite many times; it is said to be a reversible reaction that produces sodium hydroxide and hypochlorous acid. Hypochlorous acid decomposes when exposed to light, but it doesn’t decompose inside the tower, so why does the pH level inside the tower rise unexpectedly? ? ? ?
This post was last edited by Du Xiaoping on 2017-2-13 at 16:15. First of all, the two points you mentioned are incorrect: one is regarding the pH control of hyposodium, and the other is that the reaction involving hyposodium is reversible. Also, why does the pH inside the tower rise unexpectedly? It doesn’t rise inexplicably; it is alkaline by nature. The vast majority of redox reactions are irreversible, and NaOH + CI2 == NaCI + NaCIO + H2O is also irreversible. The pH of sodium hypochlorite in industrial applications is always alkaline, and it cannot be detected using test strips; this is because sodium hypochlorite is a strong oxidizing agent that directly oxidizes the test strips, turning them white. Sodium hypochlorite decomposes when exposed to light; it does not decompose inside the tower due to temperature control (via a cooling water circulation system).
The second floor is correct! If it is neutral, sodium hypochlorite decomposes ； Whether it is in a formation reaction or a decomposition reaction, sodium hypochlorite is not a reversible reaction ； If you use a test strip to measure the pH value, you’re really done for.
If the pH value is kept at neutral, sodium chlorate should be the product formed
I definitely agree with the theory, but the effective chlorine content of the sodium hypochlorite in our finished product is 13.5, with a deviation of about 0.3 from the ideal value; sometimes the pH level is around 12! Is it decomposed sodium hydroxide?
Should we set the effective chlorine content of sodium hypochlorite at around 0.085–0.12? Keep the pH at around 7–8, using water and fresh sodium hypochlorite for preparation
For our finished product, the effective chlorine content of sodium hypochlorite is around 13.5, while the free alkali content is about 0.5; the pH level is approximately 12–13. We prepare sodium hypochlorite using water and fresh sodium hypochlorite, so that the effective chlorine concentration lies between 0.085 and 0.12, with the pH kept at around 7–8. 1. What does effective chlorine refer to? Whether it’s atoms or highly charged ions, sodium hypochlorite used in industry is acidic in nature and possesses primarily oxidizing properties. 2. Why is it necessary to reduce the effective chlorine content? ? Thank you very much
1. What does effective chlorine refer to? Here it refers to clo- with a valence of +1. 2. Why is it necessary to reduce the effective chlorine level? ------To avoid unnecessary waste