[njp1990]

I've been getting no where recently with researching how bleach is brokendown under sunlight hence being stored in an opaque bottle. for my coursework i want to determine how it is broken down under sunlight and need to include the chemical formula but i cannot find anything on the internet to give me this.
The active ingredient of bleach is the Chlorate(I) ion from Sodium Chloride but I'm unsure about how the UV light will break this down. if you have any ideas that might help me understand just how this happens, anything no matter how little is greatly appreciated.

[P]

The bond involving the chlorine atom vibrates in the same frequency range as UV light usually -  thus it absorbs energy from the UV and breaks.  This is particularly true for the carbon-chlorine bond.


The bleach you have won't be sodium chloride - that's just table salt - it would be sodium hyperchorate or something like that.

[njp1990]

thanks

does the UV cause electrons to become delocalized forcing the molecule to become more positive resulting in it no longer being attracted to the Sodium as show here:

Na⁺(ClO^-) + UV Light --> Na⁺ + ClO^-

any ideas gratefully recivied

[P]

No, sorry, I don't think so  -  someone else should comment as I'm not sure, but I'm assuming it's the Cl-O bond that gets busted buy the UV.  Basically most covailent Cl bonds degrade under UV  - it absorbs the UV and breaks.  I guess in this case if the Cl-O breaks then you would be left with elemental reactive O- and the Cl would form a salt with the Na.

??

[ARGOS++]

Dear All;

I can only agree with P, and that the O-Cl bond will break and release a "Chlorine-Radical", because my reference tells, that the main product by light/UV expose are: Cl₂, HCl, O₂, and few ClO₂ .
That makes only sense as mentioned above.

Good Luck!
                   ARGOS⁺⁺