Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.

Calculate the value of the acid-dissociation constant. Ka=?

The pH of 0.039M hypobromous acid (HOBr) is 5.06.

equilibrium equation for the dissociation of HOBr.

HOBr(aq)+H2O(l)⇌H3O+(aq)+OBr−(aq)

Not sure how to calc the value of Ka

1 Answer

Relevance
  • 6 years ago

    HOBr ===> H+ + OBr-

    Ka = [H+][OBr-]/[HOBr]

    pH = -Log[H+], so +Log[H+] = -5.06

    Antilog(-5.06) = 8.71 x 10^-6 = [H+] (Calculator)

    Then [OBr-] = 8.71 x 10^-6 also.

    Ka = (8.71x10^-6)(8.71x10^-6)/(0.039) = 1.94 x 10^-9

Still have questions? Get your answers by asking now.