Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Mixture of pure nitric acid and pure hydrochloric

  1. Sep 9, 2004 #1
    Hi People,
    Could someone please give me a hand with this question : Explain why a mixture of pure nitric acid and pure hydrochloric (VII) acid (HClO4) contains H2NO3(+) ions and ClO4(-) ions.

    Thanks a lot,
  2. jcsd
  3. Sep 9, 2004 #2


    User Avatar
    Science Advisor

    HClO4 is a stronger acid than HNO3. The oxygens on the HNO3 are slightly basic, so they get protonated by the HClO4 to give the observed species.
  4. Sep 9, 2004 #3


    User Avatar
    Science Advisor
    Gold Member

    Movies is right. There is always a stronger acid than a weaker one, so the weaker one can behave a base towards the strong acid.

    You may wonder why the oxygens on HNO3 is more basic than that of HClO4. It is likely that chlorine has greater electronegativity than nitrogen, so the electronegativity totals are greater in HNO3. This may be the cause.

  5. Sep 9, 2004 #4


    User Avatar
    Science Advisor
    Homework Helper

    Yes, think in terms of the stronger conjugate acid -base pair inclusive of the overall reaction.

    Online chemistry resource
    http://groups.msn.com/GeneralChemistryHomework [Broken]
    Last edited by a moderator: May 1, 2017
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook