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Redox Reaction

  1. Aug 3, 2006 #1
    When a metal displaces hydrogen from a non-oxidizing strong acid, which substance is the oxidizing agent? Thanks :smile:
  2. jcsd
  3. Aug 3, 2006 #2
    To first solve this problem, you should try and come up with an example equation.

    For example: Copper and Sulfuric Acid.

    So when the ions "split apart", you have hydrogen ions and copper metal, so there's only one way each of those elements could be oxidized/reduced.

    And remember, an oxidizing agent is personally being reduced.

    (Technically, copper sucks as an example since there's two ways it can be changed... but I hope I got my point across)
  4. Aug 3, 2006 #3
    Copper does not react with sulfuric acid at room temperature. Only in the hot concentrated acid does it react and under these conditions sulfuric acid is a sufficient oxidizing agent.

    Take the example of Zn and HCl.

    Zn + HCl --> ZnCl2 + H2

    Zn has an oxidation number of 0 in Zn and oxidation number of +2 in ZnCl2. Because it is moving to a more positive state, it is being oxidized. Therefore zinc is the reducing agent. H has an oxidization number of +1 in HCl and an oxidation number of 0 in H2. Because it is moving to a more negative state, it is being reduced. Therefore, it is the oxidizing agent.

    If are you uncertain as to how to calculate oxidation numbers, your textbook is sure to explain it.

    Hydrochloric acid may be labeled as a "non-oxidizing acid" but this is just in regards to the more noble metals that are below hydrogen in the activity series like copper. When it reacts with a more active metal, it is indeed the oxidizing agent. Nitric acid is considered an "oxidizing acid" because it has the peculiar ability to react with some metals that are below hydrogen in the activity series.
  5. Aug 3, 2006 #4
    i think the problem here is: what means oxidation and reduction and what does an oxidizing agent and a reducing agent.
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