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Polyprotic Acids & Bases

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    The name "polyprotic" literally means many protons.

    • Calculating the pH of the Solution of a Polyprotic Base/Acid
      Thus far, we have been discussing problems and answers in equilibria--perhaps the most popular type of problem being how to find the pH of a weak acid solution given a certain concentration of a molecule. However, those problems in particular usually only involve what is called a monoprotic acid. with only one ionizeable hydrogen atom. Polyprotic Acids and Bases allows for two or more ionizeable hydrogen atoms.
    • Polyprotic Acids
      Polyprotic acids contain more than one mole ionizable hydronium ions per mole of acids.
    • Polyprotic Acids And Bases
      The name "polyprotic" literally means many protons. Therefore, in this section we will be observing some specific acids and bases which either lose or accept more than one proton. Then, we will be talking about the equations used in finding the degree of dissociation. Finally, with given examples, we will be able to approach problems dealing with polyprotic acids and bases.
    • Polyprotic Acids & Bases
      According to Brønsted and Lowry an acid is a proton donor and a base is a proton acceptor.  A monoprotic acid is an acid that can donate only one proton, while polyprotic acid can donate more than one proton. Similarly, a monoprotic base can only accept one proton, while a polyprotic base can accept more than one proton.

    Thumbnail: % species formation calculated with the program HySS for a 10 millimolar solution of citric acid. pKa1 = 3.13, pKa2 = 4.76, pKa3 = 6.40. (Public Domain; Petergans).

    Polyprotic Acids & Bases is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by LibreTexts.

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