Question

The boiling point of aldehyde and ketones depend upon:
A.Intermolecular dipole-dipole repulsion
B.Intermolecular dipole-dipole attraction
C.Intermolecular induced dipole-dipole attraction
D.None of these

Answer 1

Hint: To answer this question, you should recall the different types of intermolecular forces. You should also know the properties of aldehydes and ketones. Both aldehydes and ketones contain a carbonyl group which has an electronegative oxygen.

Complete step by step solution:
Intermolecular forces refer to the attractive and repulsive forces that arise between the molecules due to interaction. The boiling point of molecules depends on the intermolecular force of attraction, stronger the force, higher is the boiling point.
Boiling points of aldehydes and ketone depend on intermolecular dipole-dipole attraction. This is because of electronegative oxygen attached to the carbon atom. Dipole-dipole interactions are attractive forces among polar molecules.
Polar molecules have permanent dipoles resulting from differences in the electronegativities of the atoms that are associated with a covalent bond. In this type of attraction, the partially positive portion of one molecule is attracted to the partially negative portion of another molecule.

Hence, the correct answer to this question is option B.

Note: You should know about the other types of Intermolecular forces
1.Ion-Dipole Interactions: These interactions arise between ions and polar molecules. The strength of this interaction is proportional to The magnitude of the dipole moment, size disparity and charge disparity of an ion
2.Ion Induced Dipole Interactions: A non-polar molecule is polarized by an ion placed near it due to induction. Now after this polarization, both behave as induced dipoles.
3.Dipole Induced Dipole Interaction: Non-polar molecules are transformed into induced dipoles due to the presence of a polar molecule nearby.
4.Dispersion Forces or London Forces: Arises due to the movement of electrons thus creating temporary positive and negative charged regions.