Sciencemadness Discussion Board

NaDCC as a strong bleach replacement

wg48 - 26-9-2017 at 05:33

I want to use sodium Dichloroisocyanuric acid as a replacement for strong bleach. It has a PH of 6 to 7 and the acid pKa of isocyanuric acid is 6.88, 11.4 and 13.5 (from wiki). I don’t want to do the horrible cubic equation so I estimate I need to add to each mole of NaDCC 2 moles of NaOH to neutralise the acid and an extra 3 moles to make it equivalent to bleach.

Have I got that about correct?

Edit: That shoud have been 2 + 2 moles but apparently wrong in both cases.




[Edited on 26-9-2017 by wg48]

woelen - 26-9-2017 at 06:37

In total I would add only a little bit more than 2 moles of NaOH, unless you want the solution to be VERY alkaline. The acid you are talking about is very weak and there will be extensive hydrolysis. Add 2.5 moles of NaOH to 1 mole of NaDCC and then I'm quite sure that you are quite close to the properties of bleach.

wg48 - 26-9-2017 at 07:32

I guess I don't understand the figures I gave and/or they are wrong. I will try your suggestion first. Thanks.