Traditionally, Sodium bisulfite ( NaHSO3
) is used to destroy excess Hypochlorous acid ( HOCl ) in bleach solution :
HOCl + NaHSO3
NaCl + H2
Can Hydrogen peroxide ( H2
) be used instead ?
If yes, it is a much “greener” reagent and leaves no by products in solution to be separated :
2HOCl + H2
O + Cl2(g)
I tried the above using household bleach as a source of HOCl at room temperature. The reaction was immediate but of short duration with much effervescence and a strong smell of chlorine. On cessation, excess H2
was added, but no further effervescence occurred, possibly suggesting that ALL the HOCl was destroyed. There was no smell of chlorine. On adding MnO2
black powder ( catalyst ), caused the formation of a stream of bubbles, no smell of chlorine, indicating that the excess H2
was dissociating into H2
O and O2
O + O2(g)
The above is not mentioned in any related examples on the internet.