Identify the correct decreasing order of boiling points for the following compounds: (i) CH ₃ CH ₃ (ii) CH ₃ CH ₂ CH ₂ CH ₃ (iii) ( CH ₃ )₃ CH

Step-by-step solution

The boiling point of alkanes increases with an increase in molecular mass due to stronger van der Waals forces of attraction. Thus, compounds with four carbon atoms, n-butane (ii) and isobutane (iii), have higher boiling points than the compound with two carbon atoms, ethane (i). Among isomeric alkanes, branching decreases the surface area of the molecule, which leads to weaker van der Waals forces and a lower boiling point. Therefore, the straight-chain isomer n-butane (ii) has a higher boiling point than the bran