Chapter 22, Problem 4TC

Rank the following organic molecules in order of increasing solubility in water:

To determine

The rankingof the molecules in order of their solubility in water.

Answer to Problem 4TC

Solubility of Amolecule is highest then B and C has least solubility. increasing order of solubility in water is $\text{C<B<A}$.

Explanation of Solution

Fig.(1)

In Fig.(1)

A) The Oxygen atom is available to accept hydrogen bonding with water molecule. The number of lone pair is more so it has tendency to attract water molecule is more than B which has only one lone pair of electron.

B) The Nitrogen atom with one non-bonding pair of electron is available to form hydrogen bonding with water molecule. Hence it will form more hydrogen bonding than that of C.

C) In molecule C there is no availability oflone pair and the molecule is already in stable form fulfilling the positive and negative charge by the atoms present in the molecule. Hence it is least soluble due to least availability of lone pairs for forming hydrogen bonding.

Conclusion:

Therefore, solubility of A molecule is highest then B and least solubility is of C.