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Acids & Bases: Arrhenius, Brønsted-Lowry, and Lewis

  1. May 8, 2006 #1
    Problem: Complete Table 1 by noting how each theory defines acids and bases. Also, list chemical reactions that demonstrate the action of each acid or base. For example, in the reaction HA --> H+ + A-, HA acts as an Arrhenius acid.

    Firstly, I'd like to check my answers for the chemical reactions part.

    Arrhenius:

    Acids- HA --> H+ + A-
    Bases- XOH --> X+ + OH-

    Bronsted-Lowry:

    Acids- ?
    Bases- ?

    This is all that was listed:

    HCl + H2O <===> H3O+ + Cl-

    HNO3 + H2O <===> H3O+ + NO3-

    HC2H3O2 + H2O <===> H3O+ + C2H3O2-

    NH3 + H2O <===> NH4+ + OH-

    I don't really understand them though...

    Lewis:

    Acids- HNO3 => H+1 + NO3-1
    Bases- ?

    To be honest, I don't really understand what I'm doing. :blushing: I started reading what I was assigned but I got stuck on Bronsted-Lowry's theory so I took out the book my public school loaned me. Since this is a new chapter, I started off reading the basics and worked my way up to the three theories mentioned on my lesson page. Doing so only manged to confuse me more because now I'm wondering where the "A" and "X" are coming from in my first answer.

    Maybe someone could explain this to me or give me some sites?:smile:
     
  2. jcsd
  3. May 9, 2006 #2
    :uhh: Um...
     
  4. May 9, 2006 #3

    GCT

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    the arhenius definition refers to proton transfer, bronsted to the acid/base contribution to the hydronium concetration in water (pH), the lewis definition is defined by the acid being the acceptor of the lone pair electrons that are donated by the base to form a coordinate covalent bond.

    Usually in the lewis definition the bases are denoted as "B" with the lone pair component, the acid is a times denoted as A and the resulting adduct is A-B
     
  5. May 10, 2006 #4
    :surprised The browsted lowry theory is an acid base definition in respect to proton transfer. an acid is class as a solution that :bugeye: under normal conditions will donate protons. a base being the opposite is one that will accept protons.:rofl:
     
  6. May 10, 2006 #5

    Gokul43201

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    I believe you've got these interchanged.
     
  7. May 10, 2006 #6

    GCT

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    Perhaps, it's just that the op suggested that the info was from the text, and accordingly he/she had denoted those characteristics for Bronsted and Arrehnius respectively. My internet connection is desparately slow at the moment, so I'm going to need to update myself with a text when I have the time.
     
  8. May 11, 2006 #7

    Gokul43201

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  9. May 11, 2006 #8

    GCT

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    yeah, my mistake, sorry about that.
     
  10. May 11, 2006 #9
    The site I was given seems to be rather good this time so I think the misunderstanding is all on me this round.:rofl: I'm just not very good with formulas and understanding what's going on. For some reason, when I look at the formulas I have written down, my mind goes blank. I haven't the slightest idea of what I'm looking at.:redface:
     
  11. May 11, 2006 #10
    And oh, what am I to do for the Bronsted-Lowry theory? Does it really matter which chemical reaction I list for what because I believe I have to put one for the acid side of the chart as well as the base?:smile:
     
  12. May 12, 2006 #11
    Which of the three theories is applicable to the greatest number of acids and bases? Explain your reasoning.

    Lewis? I'm scanning over the Chemistry section of Southwestern's Volume Library and that's the only one it mentions.

    "A more general definition for acids and bases is called Lewis acids and bases."

    Does it simply fill in the holes the other two couldn't?
     
  13. May 12, 2006 #12

    GCT

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    yep, it's the lewis definition and yes to the second.
     
  14. May 14, 2006 #13
    How am I supposed to know what's what?:bugeye:

    Write chemical formulas representing each of the six types of compounds listed below.

    I may have overlooked this but I haven't the slightest idea of how I'm to just start naming examples that haven't already been used.:redface:
     
  15. May 15, 2006 #14
    What compounds are you referring to?
     
  16. May 15, 2006 #15
    Arrhenius acid
    Arrhenius base
    Brønsted-Lowry acid
    Brønsted-Lowry base
    Lewis acid
    Lewis base
     
  17. May 16, 2006 #16
    Which of the three theories is applicable to the greatest number of acids and bases? Explain your reasoning.

    Lewis's theory is applicable to the greatest number of acids and bases because Arrhenius and Bronsted-Lowry's theories limit acid/base reactions to a transfer of hydrogen ions while Lewis's includes electrons.

    Right, wrong? :smile:
     
  18. May 17, 2006 #17
    "Arrhenius acids are limited by having to be in aqeous solution. Lewis acids can be a "real stretch" sometimes and are not nearly as typical as Bronsted-Lowry acids."

    That's the response I got... I'm to resubmit my work and fix number two up but I can't simply reword that so I've been searching around for info. I can't seem to find exactly what I'm looking for though.
     
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