The presence of CuO in Chlorine water, I believe favors the production of HOCl:
[1] Cl2 + H2O <---> H(+) + Cl(-) + HOCl
[2] CuO + 2 HCl --> H2O + CuCl2
over the decomposition of HOCl. More HOCl per [1] means more Cl2. Now, add H2O2:
HOCl + H2O2 ---> H2O + O2 + HCl
to move reaction [1[ to the right and form O2.
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Here is a reference from Mellor, "A comprehensive treatise on inorganic and theoretical chemistry", (Volume 2), page 46, on the action of CO2 on
Bleaching powder:
"If the bleaching powder or the filtered soln. be treated with very dil. nitric, hydrochloric, or sulphuric acid, just sufficient to neutralize the
free and combined lime, hypochlorous acid, HOC1, is formed : Ca(OCl)Cl+HCl=CaCl 2 +HOCl, and
the soln. smells of hypochlorous acid but not of chlorine. The hypochlorous acid can be separated by distillation. If an excess of acid be present,
the hypochlorous acid is decomposed, forming water and chlorine : HOCl+HCl=H 2 0 + Cl 2 . Dry carbon dioxide has little or no action on dry bleaching
powder, but with moist carbon dioxide at 70, most of the chlorine is removed, although this gas has no action on calcium chloride. According to R. L.
Taylor, 13 the action of carbon dioxide on bleaching powder solid or soln. is like that of any other acid, for hypochlorous and hydrochloric acids are
produced and these decompose one another with the evolution of chlorine."
LINK:
http://www.ebooksread.com/authors-eng/joseph-william-mellor/...
[Edited on 10-3-2012 by AJKOER] |