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Homework Help: Net ionic equation and chlorine gas

  1. Nov 18, 2007 #1
    1.Chlorine gas is bubbled through an aqueous solution of sodium iodide.
    2.Barium hydroxide is used to neutralize sulfuric acid.
    Ba(OH)2(aq) + H2SO4(aq) -> BaSO4(s) + H2O(aq)
    ­ Ba(aq) + 2OH(aq) + SO4(aq) -> BaSO4(s) + O(aq)

    1.The reason im having trouble with this equation is because of the chlorine gas. On the Qualitative Solubility Rules, it dosen't state anything about gases so I dont know if it will form precipitate or just soluble.

    2. for number two can someone just confirm me if i did the equation right?(I didnt add the charges because I couldn't)

    edit: oh one more thing. theres another question that states a iron nail was added to sulfuric acid...how do i know if iron is 2+ or 3+?
    Last edited: Nov 18, 2007
  2. jcsd
  3. Nov 18, 2007 #2


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    #1. Not sure, but one guess is maybe chlorine gas is soluble enough to form HClO, an acid, and an oxidizer; possibly then oxidizing the iodide to iodine. Actually, something different might happen, so as stated, only a guess.

    #2. You are looking for Ba(+2) + SO4(-2) ==> BaSO4
    Your showing of the hydroxide and the oxygen don't seem to be meaningul. Is the reaction occurring in alkaline solution?

    Your iron nail in sulfuric acid may allow one of those ions (ferric or ferrous) to form. There is a test for this, but I don't remember it. You learn that test in your qualitative inorganic analysis in your General Chemistry course; so if you don't know the test now, you soon will know it.... something about ferrous ion, sulfuric acid, and nitric acid.
  4. Nov 18, 2007 #3
    sorry i dont get what your trying to tell me for number 2.
    the question states that Barium hydroxide is used to neutralize sulfuric acid. so how are OH and O meaningless? is there a explanation behind it?

    so for the question regarding the iron and sulfuric acid, theres no way of telling if it is stating "ferric" or "ferrous" without doing the test?
    Last edited: Nov 18, 2007
  5. Nov 18, 2007 #4


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    You are essentially showing the reaction of Barium ion with Sulfate. Really, you may leave off the showing of the hydroxide and formation of the water. The oxygen on the rightside of your reaction is not useful. I misunderstood part of what you showed by not reading your reaction carefully. So, your reaction of the base (Ba(OH)2) with the acid (H2SO4) will give the insoluble salt and water.
    The ionic reaction of interest is Ba(+2) + SO4(-2) ----> BaSO4

    You want some clarity of understanding for the ferrous test, but maybe someone else understands the details of that test. If you are in General Chemistry, you either did learn it, or you soon will learn it.
  6. Nov 19, 2007 #5
    chlorine is very soluble in water. ClO- will oxidise I- to I2.

    the net ionic equation of all neutralisation reactions bbetween acids and alkalis is:

    H+ + OH- ------> H2O

    H+ comes from the acid and OH- comes from the alkali.

    the iron added is simply iron, but not an ion. when it reacts with sulphuric acid, ions are produced. the ion produced is mainly Fe2+

    but if you leave the Fe2+ solution in the air for a while, it gets oxidised to Fe3+.

    Fe2+ is very pale green and Fe3+ is very pale yellow. It is hard to distinguish between them though. try putting a white paper sheet behind the test tube, it might help to see the colour.
    but here precipitation also occurs because BaSO4 is insoluble in water.

    Ba2+(aq) + SO42-(aq) -----> BaSO4(s)

    in ionic equations, you show only the ions taking part in the reaction, the ions not taking part are called spectator ions.
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