Question

Arrange the following in increasing order of boiling points

Answer 1

The correct increasing order is
$\left(i\right)<\left(iv\right)<\left(ii\right)<\left(iii\right)$
We know that with increase in the extent of Hydrogen bonding, there is an increase in boiling point. By that logic, both $\left(ii\right)$ and $\left(iii\right)$ must have higher boiling points as they can form Hydrogen bonds. $\left(iii\right)$ can form a much extensive network of H-bonds than $\left(ii\right)$ due to the presence of an extra electronegative $O$ atom. In $\left(iv\right)$, $Cl$ atom is not able to form H-bonding due to its large size, but it can form dipole-dipole interaction with other molecules of the same compound. This also elevates the boiling point to a lesser extent.