Thread: Chlorine/Sodium Hypochlorite

We recently had an issue in my work place where a water cooler jug contained water with high readings of chlorine (50ppm), there's no foul play suspected, and its been determined that the water jug had residue from the chlorine-based product used to disinfect the water prior to it being refilled.

Anyway, I have to questions, which I have not been able to determine.

1) Someone in our office, who uses the water from the cooler on a regular basis to make his coffee believes that if he had used this water with such a high level of chlorine, that it would have produced Chlorine Gas after being heated up in the coffee maker. Is that possible? Although this may be a taboo question, I thought that it would not be as simple as heating heavily chlorinated water.

2) Does chlorine sink or rise in water?

3) I know this is junk science, but someone decided to test the water with their swimming pool strips, and took a sample of the water home with them on a hot summers day, and tested it about 24 hours later. The bottle was sealed the entire time. How would that effect how the chlorine dissolved, if any?

3a) also the person said that they determined that the water was over 50ppm, as when they tested the water from the cooler, they diluted 2ml of that water (with chlorine) with 18ml of non-chlorinated water, which when tested with the pool strips (which only provide a reading of up to 10ppm), produced a reading of 5ppm, thus, he says that this determined that the water in the cooler was over 50ppm. Junk science, or sound theory?

thanks!

Originally Posted by Radelaide

1) Someone in our office, who uses the water from the cooler on a regular basis to make his coffee believes that if he had used this water with such a high level of chlorine, that it would have produced Chlorine Gas after being heated up in the coffee maker. Is that possible? Although this may be a taboo question, I thought that it would not be as simple as heating heavily chlorinated water.

Putting the water through a coffee machine would have boiled off pretty much all the chlorine. (The minute quantities of chlorine gas would not have been visible in the air and I imagine the smell of coffee would have covered up any smell.)

Originally Posted by PhDemon

1) Chlorine is soluble in water and heating solutions of gas in water does tend to decrease the solubility leading to the gas coming out of solution (the opposite effect to heating solutions of inorganic salts).
2) Chlorine dissolves in water and is in solution everywhere not sure what you mean by sink or rise.
3) If the sealed vial was heated the chlorine would be in the air above the liquid, when cooled and still sealed it would redissolve, if the solution was hot and you opened the vial to test it the chlorine in the air above the liquid would have been released and you would have smelled it.
4) If you got 5 ppm from 2ml of the contaminated water in 20 ml volume after dilution the concentration in the contaminated water is 50 ppm.

Thanks for the response, I guess some follow up:

1) Obviously Coffee is heated at a more significant level (200 F/100 C) than a pool or spa (Roughly 100 F/38 C), and in my scenario, obviously the level of chlorine would (hopefully! lol) be much less in a pool/spa. I guess my question is, what is the tipping point at which having chlorine in water at a certain high temperature will create noxious gas? I'm sure we've all been to an indoor pool and have had to deal with the unpleasant smell of chlorine... is that harmful in anyway?

2) What I meant was, in my scenario, where chlorine has mixed with water, will the chlorine 'collect' in one certain area (i.e. the bottom of the jug), or will it disperse evenly in the water. What I'm getting at is, will the concentration of chlorine be greater in one area than another (i.e. will the chlorine have sunk to the bottom of the water jug, and thus when the first person goes to fill there bottle, they will experience a higher concentration of chlorine then the following person.
- Chlorine is 1.5 times as heavy as water
- I'm guessing this means it would sink, but how long would it take to sink? The water jug in 18.9L, and had been sitting on the opposite end prior to use (i.e. its 'bottom' opposite its spout, the water jug was turned over and placed on the cooler roughly 3 hours before the first person 'attempted' to drink it.

3) Would waiting 24 hours to check the ppm level of the water, which has been in an unrefrigderated, sealed bottle which would have experience mild termpature change provide reliable results? (I realize this might be a subjective question....)

4)