jimmyboy - 18-4-2004 at 00:49
Will this work if I keep things cold?
Ca(ClO)2 + NaOH ---> NaOCl + Ca(OH)2
or will gas be evolved?
man do i need a chemical reaction database of some sort - bleh
Pyrovus - 18-4-2004 at 00:54
Seems OK to me - calcium hydroxide is quite insoluble in aqueous solution, so it will precipitate out when you add NaOH to Ca(OCl)2, leaving NaOCl
behind in solution. However, I should point out that NaOCl is only stable in solution - if you try to evaporate the solution, it'll evolve O2,
leaving NaCl behind.
fritz - 18-4-2004 at 01:03
If you want to get your NaOCl in a higher purity (means with a smaller content of Ca) maybe you should use Na2CO3 or better Na2SO4 instead of NaOH
because the solubilities of Ca-carbonate/sulfate are very small!
jimmyboy - 18-4-2004 at 01:15
Thats a pretty good idea -- Sodium Bicarb is far easier to acquire than Lye - probably cheaper too (and not as nasty)
I thought if you boil hypochlorites you create chlorate and chloride Pyrovus?
[Edited on 18-4-2004 by jimmyboy]
Pyrovus - 18-4-2004 at 01:29
True - if you heat hypochlorites to 70°C, then they decompose to chlorate and chloride. However, I was referring to what happens if you simply leave
the solution lying around below this temperature until all the water's gone.
jimmyboy - 18-4-2004 at 10:26
Well lets see - the Pool Shock is 450 grams at 45% - 202.5 grams = roughly 1.41 mole = 1.41*84 = 118.4 grams * 2 (2 hypochlorite ions per calcium ion
only one for sodium) = 236.8
so it looks like i mix one part bicarbonate to every two parts shock - if the bicarb is pure that is - sound about right?
DDTea - 18-4-2004 at 13:29
I've tried doing this--reacting Calcium Hypochlorite with NaOH. It works, yes, but it is a pain. Make sure you dissolve the Ca(OCl)2 in warm
water, otherwise it simply won't dissolve and you'll have an annoying burny mess. Adding the the NaOH or whatever you choose isn't so
hard...but filtering can take a long time ( i assume you are using coffee filter).
jimmyboy - 18-4-2004 at 18:32
Well i went ahead and tried the Calcium Hypo + Sodium Bicarb route.. nothing -- Sodium Hypo is suppose to be yellowish so i know it didnt happen - the
water was made warm - oh well i will try hydroxide next..
DDTea - 18-4-2004 at 18:39
If the water changed temperature, a reaction certainly did take place! Did you notice a precipitate? In the amateur lab, sometimes the chemicals
aren't as pure as they should be, and so the colors may be off. You might have had more success than you think.
jimmyboy - 18-4-2004 at 19:20
No i placed reactants in warm water to help it along - just tried hydroxide as well - just a bubbly mess - not very yellow at all - i guess i could
make concentrated sodium hypo using the hydroxide in a solution and then bubbling chlorine through it.
BromicAcid - 18-4-2004 at 20:08
Just remember to keep the reaction mixture cool otherwise you get appreciable chlorates too.