1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

General organic chemistry-acidity.

  1. Dec 14, 2016 #1
    1. The problem statement, all variables and given/known data
    In mfcd00007137-medium.png is more acidic than images?q=tbn:ANd9GcT75cX0p0PJDN6DLbg4OknmfSJ-VgSx530pLeEXzymVuUJCSFfs.png but In 300px-4-Nitrophenol_acsv.svg.png (para nitro phenol) is more acidic than mfcd00011688-medium.png (ortho nitro phenol) why?

    2. Relevant equations
    in ortho nitro benzoic acid due to -I and -M effect it is more acidic than it's para species (-I effect more in ortho position) .

    3. The attempt at a solution
    In the latter compounds, due to intra molecular H-bonding, para compound is more acidic than that of the ortho compound. my doubt is in ortho nitro benzoic acid, isn't there any intra molecular H-bonding cause a carboxylic acid can form H-bonding so does the nitro compound. please solve my query :/
  2. jcsd
  3. Dec 18, 2016 #2


    User Avatar
    Science Advisor
    2017 Award

    For o-nitro benzoic acid and o-nitro phenol, try drawing out all the bonds (including N-O and O-H bonds) to see what the intramolecular hydrogen bonding looks like. You may see a problem with o-nitrobenzoic acid but not o-nitro phenol.
  4. Dec 20, 2016 #3
    sorry i don't understand..please explain further :/
  5. Dec 20, 2016 #4


    User Avatar

    Staff: Mentor

    Have you tried to draw what Ygg suggested?
  6. Dec 20, 2016 #5
    5TXTl.gif ok..this ortho nitro benzoic acid. there is this unwanted -ve sign here. main-qimg-53eee499d40b785efeb800e853e2f5b9?convert_to_webp=true.gif where as here in ortho nitro phenol, it could easily form intramolecular H-bonding...sorry! still, i didnt get the point! do explain me! it would be of great help :)
  7. Dec 20, 2016 #6


    User Avatar
    Science Advisor
    2017 Award

    For the nitro benzoic acid, draw the O-H bond. Also, keep in mind the preferred angles for each bond. You should see the problem.

    If you're still not getting it, try building a model of you have a model kit.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted