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Chromic Acid

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    39359
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    Chromic acid is the oxoacid that has the molecular formula H2CrO4 and the structural formula:

    chromicacid1.png

    Chromic acid is unstable and, therefore, must be generated in situ when needed, using one of the following methods.

    1. Reaction of chromium (III) oxide with water

    chromicacid2.png

    2. Reaction of potassium or sodium dichromate with sulfuric acid

    chromicacid4.png

    Chromic acid is a strong oxidizing agent, used to oxidize many classes of organic compounds, the most common of which is alcohols. There are two generalizations that help understand oxidation of alcohols using chromic acid.

    1. Any alcohol containing at least one alpha hydrogen is oxidized by chromic acid, meaning tertiary alcohols are not oxidized by chromic acid.

    2. Any organic product formed whose molecule has at least one hydrogen atom bonded to the carbonyl carbon is further oxidized by chromic acid.

    Oxidation of a primary alcohol by chromic acid results in a carboxylic acid as the organic product.

    eg:

    chromicacid5.png

    Oxidation of a secondary alcohol by chromic acid results in a ketone as the organic product.

    eg:

    chromicacid6.png

    see also chromate ester, pyridinium chlorochromate


    This page titled Chromic Acid is shared under a All Rights Reserved (used with permission) license and was authored, remixed, and/or curated by Gamini Gunawardena via source content that was edited to the style and standards of the LibreTexts platform.

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