Zinc - 22-5-2006 at 10:01
Today I mixed a solution of NaOCl and FeSO4 and got a red/brown precipitate and the smell of chlorine apeared.
Can you please tell me what are the products?
Thank you in advance.
12AX7 - 22-5-2006 at 12:51
[O(-2)Cl(+1)]- + 2Fe(2+) + H2O = Cl- + 2Fe(3+) + 2OH-
Sodium and sulfate are spectator ions so I'm not writing them (they go through unchanged). Note I've written out the formal charge of the
hypochlorite to illustrate that chlorine goes from a higher state to plain chloride, in the process oxidizing the iron. The iron goes from ferrous to
ferric, which is an acidic ion so would rather combine with water and nearby hydroxyls (such as produced in the above reaction) to make ferric
hydroxide, a brown precipitate. 2/3rds of the iron remains in solution, and because it tends to attract the hydroxyls, it leaves hydrogen ions
floating around (due to the reaction H2O = OH- + H+), which are acidic. Some of these ions combine with the hypochlorite and chloride ions to form a
chlorine molecule as 2H+ + OCl- + Cl- = H2O + Cl2, which evaporates and smells like chlorine.
Tim
[Edited on 5-22-2006 by 12AX7]
Zinc - 23-5-2006 at 06:49
Thank you for the answer.
jaswin - 23-5-2006 at 07:40
