# Bleach - does the chlorine evaporate? **URL:** \ **Category:** Factual Questions\ **Created:** [September 7, 2014, 11:15pm UTC](https://boards.straightdope.com/t/bleach-does-the-chlorine-evaporate/697803 "2014-09-07T23:15:25Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Velocity](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/velocity/32/18006_2.png) [@Velocity](https://boards.straightdope.com/u/Velocity)\ **Post date:** [September 7, 2014, 11:15pm UTC](https://boards.straightdope.com/t/bleach-does-the-chlorine-evaporate/697803/1 "2014-09-07T23:15:25Z")
Say you leave a puddle of bleach lying on the ground for a week. Would all the chlorine evaporate and simply leave behind inert, pH-neutral, useless powder? ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [September 7, 2014, 11:40pm UTC](https://boards.straightdope.com/t/bleach-does-the-chlorine-evaporate/697803/2 "2014-09-07T23:40:51Z")
it would oxidize whatever it could and be used up likely before all the water (95%) has evaporated. ---
**Author:** ![Senegoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senegoid/32/6606_2.png) [@Senegoid](https://boards.straightdope.com/u/Senegoid)\ **Post date:** [September 8, 2014, 2:40am UTC](https://boards.straightdope.com/t/bleach-does-the-chlorine-evaporate/697803/3 "2014-09-08T02:40:42Z")
[Prior (brief) thread on the subject](http://boards.straightdope.com/sdmb/showthread.php?t=579725), discussing in detail the chemical reaction. (ETA: See especially Posts #2 and 5.) Bleach is a solution of sodium hypochlorite, NaOCl. It is rather unstable, and rather quickly decomposes to oxygen and sodium chloride in solution. > [@(from that thread)](#): > > The decomposition (loss of O2) follows the following reaction: > > 2NaOCl –\> O2 + 2NaCl When you jump into a swimming pool, note the cloud of little bubbles that appears. Jumping into plain water doesn’t create all that many little bubbles. It’s the chlorine (actually, sodium hypochlorite) in the water breaking down and releasing all that oxygen. The oxygen (some of which is dissolved in the water) can oxidize impurities in the water. I suppose the chlorine would to, as it’s also a powerful oxidizer. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [September 8, 2014, 6:11am UTC](https://boards.straightdope.com/t/bleach-does-the-chlorine-evaporate/697803/4 "2014-09-08T06:11:26Z")
> [@Senegoid](#): > > [Prior (brief) thread on the subject](http://boards.straightdope.com/sdmb/showthread.php?t=579725), discussing in detail the chemical reaction. (ETA: See especially Posts #2 and 5.) > > Bleach is a solution of sodium hypochlorite, NaOCl. It is rather unstable, and rather quickly decomposes to oxygen and sodium chloride in solution. :dubious: How come bleach smells of chlorine, then? ---
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [September 8, 2014, 7:00am UTC](https://boards.straightdope.com/t/bleach-does-the-chlorine-evaporate/697803/5 "2014-09-08T07:00:47Z")
> [@njtt](#): > > :dubious: How come bleach smells of chlorine, then? There is a leakage of Cl. Most of the smell from bleaching is from after the chlorine has hit organics… There’s smelly stuff like fatty acids that become chlorinated and they have the chlorine smell after that. ---
**Author:** ![Nava](https://avatars.discourse-cdn.com/v4/letter/n/da6949/32.png) [@Nava](https://boards.straightdope.com/u/Nava)\ **Post date:** [September 8, 2014, 8:34am UTC](https://boards.straightdope.com/t/bleach-does-the-chlorine-evaporate/697803/6 "2014-09-08T08:34:55Z")
A leakage of Cl[sub]2[/sub], please. Cl would be an isolated atom, the molecule is Cl[sub]2[/sub].