Chemical Forums
Chemistry Forums for Students => Inorganic Chemistry Forum => Topic started by: iheartsludge on December 28, 2011, 11:18:06 AM
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Acidification of sodium hypochlorite with hydrochloric acid.
1. NaOCl + HCl = NaCl + HOCl
2. HOCl + HCl = H2O + Cl2
overall: NaOCl + 2 HCl = Cl2 + H2O + NaCl
Question:
Is the overall reaction of NaOCl and 2 HCl proceed to 100% conversion to Cl2? 95%? Just trying to figure out if HCl is needed in any excess amount.
Thanks.
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You get an equilibrium, depending on the pH of the solution.
If you bubble chlorine gas into water, you get gaseous chlorine in solution in equilibrium with the hypochlorous acid and hydrochloric acid in solution. This is at pH of about 2. As you raise the pH, the amount of gaseous chlorine diminishes and the amount of hydrochloric acid and hypochlorous acid increases. Raise it further(usually with NaOH) and you get an equilibrium between hydochloric acid and hypochlorous acid with sodium chloride and sodium hypochlorite (this is usually at pH ~11).
Choose the pH to get the form you need (Cl2, HOCl, or NaOCl).
Hope this helps.
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Raise it further(usually with NaOH) and you get an equilibrium between hydochloric acid and hypochlorous acid with sodium chloride and sodium hypochlorite (this is usually at pH ~11).
This is a lousy wording. Hydrochloric acid is a strong one, almost always fully dissociated, hypochlorous is a weak one, with pKa around 7.5 - which means at pH 11 it is dissociated in over 99.9%. So technically the equilibrium is not between 'acids', but between conjugate bases.
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NaOCl + HCl = NaCl + HOCl
question: HOCl can --> HCl + O, T or F[/b]
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Chlorine is soluble in water forming HCl and HOCl.so you have to add extra acid to get complete chlorine bubbled.