超人 asked in 科學及數學化學 · 1 decade ago

Chlorine bleach

hypochlorous acid 能否 bleach solution (universal indicator solution)?

是否只能 bleach dye?

How about sulphur dioxide?

thx

Update:

I want to know if chlorine bleach can bleach "solution" .

2 Answers

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  • 1 decade ago
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    Since bleaches are strong oxidizing agents, they can be quite hazardous, especially when reacted with other common household chemicals.

    Mixing sodium hypochlorite with acids like vinegar or drain cleaners containing sodium bisulfate (sodium hydrogen sulfate), or even lemon juice can release chlorine. Hypochlorite and chlorine are in equilibrium in water, the position of the equilibrium is pH dependant and low pH (acidic) favors chlorine,[1]

    Cl2 + H2O H+ + Cl- + HClO

    Chlorine is a respiratory irritant that attacks mucous membranes and burns the skin. As little as 3.5 ppm can be detected as an odour, and 1000 ppm is likely to be fatal after a few deep breaths. Exposure to chlorine has been limited to 0.5 ppm (8-hour time-weighted average—40 hour week) by OSHA in the U.S.[2]

    Sodium hypochlorite and ammonia react to form a number of products, depending on the temperature, concentration, and how they are mixed. [3]. The main reaction is chlorination of ammonia, first giving chloramine (NH2Cl), then NHCl2 and finally nitrogen trichloride (NCl3). These materials are very irritating to eyes and lungs and are toxic above certain concentrations.

    NH3 + NaOCl --> NaOH + NH2Cl

    NH2Cl + NaOCl --> NaOH + NHCl2

    NHCl2 + NaOCl --> NaOH + NCl3

    Additional reactions produce hydrazine, in a variation of the Olin Raschig process.

    NH3 + NH2Cl + NaOH --> N2H4 + NaCl + H2O

    The hydrazine generated can further react with the monochloramine in an exothermic reaction:[1]

    2 NH2Cl + N2H4 --> 2 NH4Cl + N2

    Industrial bleaching agents can also be sources of concern. For example, the use of elemental chlorine in the bleaching of wood pulp produces organochlorines, persistent organic pollutants, including dioxins. According to an industry group, the use of chlorine dioxide in these processes has reduced the dioxin generation to under detectable levels.[4] However, respiratory risk from chlorine and highly toxic chlorinated byproducts still remain.

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  • 1 decade ago

    yes!

    HOCl can bleach things

    It can ionize to give OCl- ions, which is an active ingredient of bleach,

    Although HOCl does not ionize in water COMPLETELY.

    OCl- bleach things by oxidation.

    SO2 can also bleach things by reduction when it is dissolve in water or moist.

    SO2 + H2O + dye -----> SO4 2- + 2H+ + (dye-O)

    SO2 is widely used in industry.

    Source(s): My knowledge
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