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Thread: Reactions of acids/bases with water: correct use of arrows

  1. #1 Reactions of acids/bases with water: correct use of arrows 
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    Hello, my book says that all acids above H3O+ completely ionize with water so we use "--->" .
    The acids under H3O+ and above H2O are in equilibrium with water so we use " <--->".
    The acids under H2O are so weak they dont even react with water so we dont use anything.

    Now there are some exceptions! For example Na+, LI+, Ba2+, Ca2+, .... are above H2O but they dont use <---> for whatever reason.
    My book says that the metal ions of the IA & IIA groups are exceptions, so even though they are above H2O they still arent in equilibrium with water "<--->". They simply dont react with water.
    Now my question is for SO42-, this is a base, but it follows the same analogy as acids do. SO42- is under H2O & above OH-, so it should be in equilibrium with water right? So we officialy denote that with "<---->" right?

    Thanks in advance!!


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  3. #2  
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    Quote Originally Posted by mcfaker123 View Post




    Hello, my book says that all acids above H3O+ completely ionize with water so we use "--->" .
    The acids under H3O+ and above H2O are in equilibrium with water so we use " <--->".
    The acids under H2O are so weak they dont even react with water so we dont use anything.

    Now there are some exceptions! For example Na+, LI+, Ba2+, Ca2+, .... are above H2O but they dont use <---> for whatever reason.
    My book says that the metal ions of the IA & IIA groups are exceptions, so even though they are above H2O they still arent in equilibrium with water "<--->". They simply dont react with water.
    Now my question is for SO42-, this is a base, but it follows the same analogy as acids do. SO42- is under H2O & above OH-, so it should be in equilibrium with water right? So we officialy denote that with "<---->" right?

    Thanks in advance!!
    I wouldn't get too hung up on the difference between reactions that this book says go to completion and those that it says do not. As mentioned in our previous discussion it is all a single continuum. Everything, strictly, is an equilibrium process: it is just that at the extremes, the equilibrium lies so far to one side that there is little point showing it as such. There is no real convention, so far as I know, about when you use equilibrium arrows and when you use a single arrow. It's up to you. I think your book is just trying to convey, qualitatively, those reaction that are commonly seen as going virtually to completion and those that do not.


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  4. #3  
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    a reaction of acid/base with water?

    metals react with water.

    do you have more on this?
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  5. #4  
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    Quote Originally Posted by ASG141 View Post
    a reaction of acid/base with water?

    metals react with water.

    do you have more on this?
    Plenty. For people asking sensible questions, in good faith.
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  6. #5  
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    how do acid/base react with water?
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