Variation of boiling and melting points of alkanes with increase in the number of carbons
The odd-numbered alkanes have a lower trend in melting points than even numbered alkanes. This is because even numbered alkanes pack well in the solid phase, forming a well-organized structure, which requires more energy to break apart. The odd-numbered alkanes pack less well and so the "looser" organized solid packing structure requires less energy to break apart.
Why is that the alkanes containing an even number of carbons can be packed more easily compared to the alkanes containing an odd number of carbons?
Both types of alkanes can be laid next to each other; hence, why should the number of carbons even matter?
I started drawing and noticed something.
The diagram makes it pretty obvious that the alkanes with odd numbers cannot be packed efficiently.
I am not sure if this is the correct answer.