Which has the higher boiling point?
(a) CH3CH2CH2CH2CH3 or (b) CH3CH2CH2CH2CH2CH2CH2CH3
b. higher molar mass. Larger IMF (intermolecular forces)
CH3CH2CH2CH2CH2CH2CH2CH3
Rabia tesfaw
To determine which compound, (a) CH3CH2CH2CH2CH3 or (b) CH3CH2CH2CH2CH2CH2CH2CH3, has the higher boiling point, we need to examine their molecular structures and understand the factors that influence boiling points.
The boiling point of a compound depends on the strength of intermolecular forces between its molecules. Stronger intermolecular forces generally lead to higher boiling points.
In this case, both compounds are alkanes, which are hydrocarbons consisting of only carbon and hydrogen atoms. Alkanes are known for having relatively weak intermolecular forces, mainly van der Waals forces or London dispersion forces.
The boiling point of an alkane generally increases with the size or the number of carbon atoms. The larger the molecule, the greater the surface area and the more opportunities there are for van der Waals forces to occur, leading to stronger intermolecular forces.
Comparing the two compounds, we notice that compound (b) has more carbon atoms than compound (a). It is an eight-carbon alkane, while compound (a) is a five-carbon alkane. Hence, compound (b) has a larger molecular size than compound (a), and therefore, it is likely to have stronger intermolecular forces.
Consequently, compound (b) CH3CH2CH2CH2CH2CH2CH2CH3 is expected to have a higher boiling point than compound (a) CH3CH2CH2CH2CH3.