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Net Ionic Equations help

  1. Mar 28, 2006 #1
    Alright, these were asked on the test I took today, and I was just seeing if I did them correctly.

    Write the net ionic equations for the following reactions (don't need to be balanced):

    1. Solid potassium amine is added to distilled water.

    KNH2 + H2O ---> K+ + NH3 + OH-

    2. Sulfur dioxide gas is bubbled through distilled water.

    SO2 + H2O ---> H2SO3

    3. Nickel nitrate is mixed with sodium sulfide.

    Ni+ + S2- ---> Ni2S

    4. Phosphorous trihydride is combined with boron tricloride.

    PH3 + BCl3 ---> BH3 + PCl3

    For the first one, I'm thinking it might be NH4+ on the products side instead of NH3...? I'm not that confident about the second one, and I think I nailed the third one, but maybe not. For the last one, I didn't know if it would be a double replacemnet or if it would form one big molecule...If anyone notices any mistakes, big or small, please point them out =). This is my worst part of chemistry :-(
    Last edited: Mar 28, 2006
  2. jcsd
  3. Mar 29, 2006 #2


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    Staff: Mentor


    Last edited by a moderator: Aug 13, 2013
  4. Mar 29, 2006 #3
    Oh okay, thank you. So everything else is surprisingly correct then? Or were you just pointing out that one mistake?

    Al + H2O ---> [Al(H2O)6]3+

    or would it simply be:

    Al + H2O ---> Al(OH)3 + H2

    The wording is kind of messed up here. Both are sort of correct. There will be a small rapid increase initially, but then there is a sharp increase (not AS sharp as a strong acid-strong base titration, but still sharp) when it nears the equivalence point.

    You could also argue that it gradually increases and then there is that sharp increase that I was talking about. However, that sounds more like a strong acid-strong base. Therefore, I guessed A, knowing that either could technically work.

    Any more help is greatly appreciated!
    Last edited: Mar 30, 2006
  5. Mar 30, 2006 #4


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    1st probably OK, 2nd OK for sure, no idea about 4th.

    Al doesn't react with distilled water, it is passivated with Al2O3.

    Your thinking about AB wording sounds correct, it can be argued they are both OK or both wrong.

    Last edited by a moderator: Aug 13, 2013
  6. Mar 30, 2006 #5
    Thank you again! My teacher makes his tests exactly like the AP Test, except half as long. They are very difficult, which means he makes a big curve, so I always get an A :).
  7. Apr 2, 2006 #6

    1. Correct!

    2. Correct!

    3. Ni2+ + S2- --> NiS(s)
    NiS is solid black substance. It doesn't dissolve in water.

    4. PH3 + BCl3 --> PH3BCl3
    PH3BCl3 is solid, PH3 and BCl3 are gasses.
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