The boiling points of water, ethanol and diethyl ether are 100° C, 78.5° and 34.6°C, respectively. The intermolecular forces will be in the order.

Concept:

Intermolecular forces

• Intermolecular forces are the attractive and repulsive forces that arise between the molecules of a substance.
• Intermolecular forces are mainly responsible for the physical characteristics of the substance.
• The stronger the noncovalent interactions between molecules, the more energy that is required, in the form of heat, to break them apart.
• The boiling point and melting point of a substance is proportional to the strength of its non-covalent intermolecular forces i.e. the stronger the intermolecular forces, the higher the boiling point and melting point. Hence option 1 is correct.
• The strongest intermolecular force is the hydrogen bond.
• The weakest intermolecular forces are London dispersion forces.

Explanation:

So as per explained, Boiling point high intermolecular force high.

⇒ Water = 100° C

⇒ Ethanol = 78.5° C

⇒ Diethyl ether = 34.6°C

Hence, Water > ethanol > diethyl ether is the correct sequence.