There is a statement given in my textbook (Cengage, Organic Chemistry (Part 1), page 4.33) which is as follows: (I edited the statement to make it simpler)

One can account for the solubilities of o-nitrophenol, salicylaldehyde,and salicylic acid in cold water, in which they are insoluble, while in hot water they are soluble, using the concept of intramolecular hydrogen bonding. However, their para- and meta- isomers are soluble even in cold water. This can be explained by intermolecular H-bonding.

I have difficulty in understanding this statement.

How does hydrogen bonding influence the solubility in hot and cold water and moreover can we draw any conclusions about boiling and melting points of the compounds, in which one has intramolecular hydrogen bonding and the other having intermolecular hydrogen bonding?

  • $\begingroup$ Search about hydrogen bonds influencing solubility on Google! :) It'll give you some great learning resources. It also helps you to learn more about the phenomenon itself, which will catalyse your ability of applying the concept to various questions, rather than just learning the theory out of a textbook $\endgroup$ – AbhigyanC Jul 10 '18 at 17:30
  • $\begingroup$ This is a really good related question: chemistry.stackexchange.com/questions/5503/… $\endgroup$ – AbhigyanC Jul 10 '18 at 17:31
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    $\begingroup$ With intramolecular hydrogen bonding, the substance would generally be less soluble in water and would thus require a higher T for dissolution. This is because the molecules are not as able to interact with the solvent water molecules, via H bonding, as their polar functional groups are involved in an intramolecular interaction. Thus, there would be less mixing, resulting in a much smaller entropy increase upon dissolution. Thus, a higher T is required to increase the value of TdeltaS to make delta G negative. $\endgroup$ – Tan Yong Boon Jul 10 '18 at 22:59

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