I’m not aware of too many circumstances where the pH would be at 3 or lower when you are reacting chlorine gas with water. My nunbers are coming from Table 13-6 of the 6th edition of Cotton, et. al Advanced Inorganic Chemistry. BTW, many of the reactions involving the various oxo acids and anions of the halogens, in general, are of the disproportionate type.
Thank you! I shall try this out.
So the two reactions would be:
3OCl[sup]-[/sup] → ClO[sub]3[/sub][sup]-[/sup] + 2Cl[sup]-[/sup]
and
OCl[sup]-[/sup] + OCl[sup]-[/sup] —> O[sub]2[/sub] + 2Cl[sup]-[/sup]
which shows the tendency of the hypohalite ions to disproportionate
And of course the biggie is beware of mixing bleach and ammonia*, because it will make a really nasty gas, nitrogen chloride if I’m not mistaken.
*And urine counts as ammonia, as I discovered the first time I used bleach to disinfect cat pee.
As a side question, does anyone have any experience with using hydrogen peroxide as a bleaching/sterilizing agent?
color safe bleach can use peroxide.
it is very effective as a disinfectant.
The primary result of mixing ammonia with bleach would be (by disproportination) the formation of chloramine (NH[sub]2[/sub]Cl or, in the presence of excess quantities of ammonia, hydrazine (N[sub]2[/sub]H[sub]4[/sub], which is used as a rocket fuel and, as you might guess, is quite explosive). In either case, it’s not a good idea to do this on a routine basis!
People here in south Georgia have a habit of using bleach to mop their floors. Shortly after the local Hardee’s opened up, one of the closers was using bleach on the floor. It wasn’t working well, so she squirted Dawn dish detergent on the floor (Dawn has ammonia in it). She survived after a trip to the emergency room. Yep, ammonia and bleach is a bad mix.
Did they have to close the restaurant down until it was deemed safe to go back inside?
It was closed at the time. I imagine they just aired the place out with fans and rinsed down the floors with clean water. It was open the next morning- there wasn’t a 24 hour business anywhere in that town.
In the animal care industry, we use a bleach solution to clean stainless steel all the time. It’s household bleach mixed usually at 1:32 for general disinfection, or for fungal cleaning we use 1:10. Neither of these pits the stainless. Someone once accidentally used straight bleach on the first cage they were cleaning for the day, and it pitted.
I did a little food industry work more than a decade ago, so if someone has more information than I do as an example, feel free. I worked at a coffee shop, and all the plastic containers we used and re-used (for cold brewing, for concentrated espresso, for iced tea and mixers) were bleached whenever they were cleaned. Left to dry overnight and used the next day, pretty much every day. If we didn’t, the containers would all be stained darker and darker brown over time. I can’t imagine we would have passed inspections if that wasn’t deemed safe, or part of a common cleaning routine for restaurants.
Just so the OP’s sister knows, probably everything she gets served out of a plastic re-usable container at restaurants, most likely gets bleached every night.
Bleach is much more reactive at lower pH, but I don’t recommend it for most. My source is Journal of American Water Works Association, 1948, p 1051. The descrepency is, I think, in the concentrations. This article deals with <1000 ppm which, if my head math is right, is about a quarter of what Cotton says. Cotton is a good reference, I wish I had mine. According to this though, the hydrolysis of chlorine is 100% until pH is below 3.
What does Cotton cite for this?
We used a solution of household bleach and water in Africa for three years to wash our fruits and veggies. Killed all the nasty bacteria and left no after-taste. We had no ill effects from it.
It can… but I had to soak it for about a week in standard household bleach, it doesn’t happen quickly. Keep in mind that the stuff sold for household use is already diluted. Pure sodium hypochlorite would probably react much faster.
Then again, the acid your stomach naturally produces can dissolve a steel nail over time as well. So just because an acid or base can dissolve metal doesn’t mean it’s going to kill you. (I do suggest careful handling in any circumstances. Safety first.)
It will, but this is more an industrial guideline rather than an important household use one.
As in - if you’re building a reactor or a storage tank or selecting materials for pipe or whatever. You wouldn’t pick stainless for bleach or any other strong oxidizing material. I left my handy-dandy engineering textbook at work, but I would assume you’d pick something like HDPE or HDPP. Maybe glass-lined. But for incidental household use exposure, OTC bleach (which is fairly dilute) won’t do much unless you use it to wash a stainless piece over and over.
OK, there is a lot of mis-information here.
Sodium Hypochlorite dissolved in water will form a weak solution of hypochlorus acid. However, most commercial bleach solutions are buffered to be basic to keep the chlorine in solution.
Chlorine bleach will pit stainless, even at low concentrations. A lot depends on the grade of stainless, the concentration of the chlorine, temperature, and the exposure time. Don’t believe?, soak a rag in bleach and set it on a stainless sink and check it in the morning (ok, don’t, because you will ruin the sink). Not only will the chlorine cause pitting, but if the stainless is under stress, it can cause cracking (google “Chloride Stress Cracking”). Low concentrations, short exposure times, you are probably OK, but it isn’t anything to fool with. You won’t find any stainless steel on a US Navy ship (Salt Water), they use a nickel alloy called Monel.
So, bleach is relatively safe to use, but don’t mix it with ammonia, don’t drink it straight, and don’t fill a stainless pot with it. At dilute concentrations, it will be safe if it is dilute enough and the exposure is short enough, but it can cause problems.
excavating (for a mind)
That seems pretty consistent with what the thread says. I’m not sure what the misinformation was.
ETA: except that part about bleach being buffered. If you add acid to bleach, the pH will dop pretty quick because it isn’t buffered. So that’s misinformation.
So I guess it’s fairly safe to assume that a tablespoon in the rinse cycle of the dishwasher isn’t going to harm the flatware.
The first time I was warned about this was when I was working for a hotel chain and we used a commercial product distributed by Aramark that was approximately twice the concentration of normal bleach. I think it was close to 10% NaClO in water. Everybody who worked there was terrified of the stuff. They were convinced that if they got it on their hands that the only remedy would be immediate high amputation. I was repeatedly admonished not to apply it directly to stainless.
That’s not what wiki says will happenhttp://en.wikipedia.org/wiki/Sodium_hypochlorite
What I was expecting was that it would act as a base by reducing the number of H+ ions when it combined with them to form HCLO3. (But wiki shows it making lye.)
Not to nit pick but the reference sources I checked make a very clear distinction between designating sodium hypochlorite as NaOCl versus showing it as NaClO. The ClO variant simply is not correct.
Well, yes, but it probably won’t do much in the dishwasher either. A dishwasher uses what, 5-6 gallons per wash? A tablespoon of commercial bleach would be so diluted in that as to probably do nothing.