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why is Ag2SO4 insoluble?? rule is all SO4 salts are soluble except..

Discussion in 'DAT Discussions' started by tRNA, Jul 17, 2007.

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  1. tRNA

    tRNA Member

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    this makes NOOO sense whatsoever:

    the reaction of AgNO3 and Na2SO4 in H2O goes to completion because:
    a) silver sulfate precipitates
    b) H2O is a strong electrolyte
    c) it is a nutralization rxn
    d) a volatile product is formed
    e) sodium sulfate is a very strong acid

    well, i narrowed it down to A or D, but since I know from solubility rules that
    ALL sulfate salts are SOLUBLE except: Hg, Pb, Ca, Sr, Ba, and since Ag is not one of the insoluble ones, I chose d but the answer is A

    so how on earth can silver sulfate be insoluble????
    i hate when questions go against basic stuff like that, makes u feel so dumb

    plz help thanks
  2. Prometheous19

    Prometheous19 Gunslinger DMD

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    Sulfate is insoluble with Ag, Pb and Hg. Straight from my Kaplan white book.
  3. poc91nc

    poc91nc

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    Actually silver sulfate and mercurous sulfate are sparingly soluble. At least according to Linus Pauling they are.
  4. zackscoot

    zackscoot

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    AND sodium sulfate is not even an acid... so you should've picked A.
  5. tRNA

    tRNA Member

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    dude, what page was that in the white book?? on page 914 of the white book it says
    #4) all salts of the sulfate ion (SO4) are water soluble, with the exceptions of Ca, Sr, Ba, Pb.

    I also checked with examkrackers page 76 5th edition and my college textbook (Steven S. Zumdahl 6th edition page 152) Ag is not with the exceptions, i don't get it:confused:
  6. fbf

    fbf

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    silver sulfate is considered as insoluble since it does have low solubility even though it is a ionic compound.
  7. IsRaEl21

    IsRaEl21

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    silver sulfate considers to be slightly soluble even though it has a very low ksp. It's still soluble. Where are u getting that it's not. Ca2+, Sr2+, Ba2+, Ra2+, Pb are insoluble with SO4, Ag is slightly soluble.
  8. poc91nc

    poc91nc

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    See Linus Pauling's General Chemistry

    Pg 453

    It is SPARINGLY soluble...
  9. poc91nc

    poc91nc

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    Linus Pauling makes a clear distinction between soluble, insoluble and sparingly soluble


    Is this beyond the scope of the DAT.....yes...

    So, no worries!
  10. Speeddater

    Speeddater

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    This is exactly the reason I loathe some of the Qr word problems, especially a few I've been coming across in the SAT books, ugh, I feel like I'm studying to take that exam again as well. Anbody seen the movie "accepted" where a few High School kids didn't get into any college and they designed their own college. Hey, I have an idea, let's design our own dental school, and everybody gets scholarships. The only requirement is that you're a nice & friendly person! :)
  11. tRNA

    tRNA Member

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    ok thanks, I'll go to a book store, check out that book and copy all the SPARINGLY soluble ions, and when doing dat problems assume they're insoluble as that problem shows
  12. tRNA

    tRNA Member

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    that's what kaplan says...answer is A, "precipitates" means insoluble right

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