chemistry

posted by .

why ortho nitrophenol are more volatile than para nitrophenol

  • chemistry -

    Could it be that intermolecular forces in the para are lessened due to the location of the nitros?

  • chemistry -

    Along the same lines as Bob Pursley suggested but with a slghtly different view, the ortho forms a 5-membered ring with the positive H of the OH and the negative O of the NO2 group. This is a strong INTRAmolecular force (within the same molecule). The p-nitrophenol is free to form the usual INTERmolecular bonds (H bonding between the OH of one molecule and the NO2 group of another molecule) which strengthens the crystal structure of the para isomer and that leads to a higher melting point for the para isomer. The ortho isomer lacks the forces between molecules that the para isomer has and it melts lower. My first year in grad school I was given a mixture of organic chemicals to separate and identify. o-nitrophenol was one of the compounds which I separated. It was near the end of the class period, I had to go to another class, I just put the solid on a piece of filter paper, placed it in my desk and went about my other classes. When I came back two days later to tackle the job of identification, ALL of it (and I do mean ALLLLL) was gone (it had completely volatilized) and I had to go through another 3-4 hours work to separate another batch. Tough lesson to learn BUT notice that the experience stayed me for the last 60 years and I remember to this day that o-nitrophenol is both smelly AND volatile. :-)

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Volatility

    Question: A mixture of p-nitrophenol and o-nitrophenol can be separated by steam distillation. The o-nitrophenol is steam volatile, and the para iosmer is not volatile. Explain. Base your answer on the ability of the isomers to form …
  2. organic

    which phenol is the most acidic? phenol 2-methyl-6-nitrophenol 3-methyl-5-nitrophenol 2,6-dimethyl-3-nitrophenol 2,4,6-trimethylphenol
  3. chemistry

    Would you expect ortho-dimethoxybenzene or para-dimethoxybenzene to be nitrated more readily?
  4. chemistry

    Would you expect ortho-dimethoxybenzene or para-dimethoxybenzene to be nitrated more readily?
  5. Organic Chemistry

    Assuming you have a mixture of 2-nitrophenol and 4-nitrophenol, which solvent would be most suitable for recrystallization if you want to isolate 4-nitrophenol?
  6. Chemistry

    An impure sample of substance X melts at about 113 degress. Which of the substances could be X and state y Resorcinal 111 degrees Catechol 105 Nitrophenol 114 Butanamide 115 I think it is either catechol or resorcinol because as stated …
  7. Chemistry

    What is the pH of a solution prepared by dissolving 1.23g of 2-nitrophenol (FM 139.11) in 0.250 L?
  8. Important question regarding chemistry

    Explain intermolecular hydrogen bonding with reference to ortho nitrophenol
  9. chemistry

    Is bp of para and meta and ortho isomer are same
  10. Science

    Meta and para isomers are more soluble in water than ortho isomer?

More Similar Questions