Why do straight chain alkanes have higher boiling points than branched chain?

Straight chain compounds have large size and hence have large polarizability and have strong London dispersion forces hence high boiling points while branched compounds have compact structure and hence have low polarizability and have low boiling points.

Why do branched alkanes have lower boiling points than straight chain alkenes?

Branched alkanes normally exhibit lower boiling points than unbranched alkanes of the same carbon content. This occurs because of the greater van der Waals forces that exist between molecules of the unbranched alkanes. The strong repulsive forces counterbalance the weak van der Waals forces of attraction.

Why straight chain alkane has high boiling point?

This is because the intermolecular attractive forces, although individually weak, become cumulatively more significant as the number of atoms and electrons in the molecule increases. For a given number of carbon atoms, an unbranched alkane has a higher boiling point than any of its branched-chain isomers.

Why do linear alkanes have higher melting and boiling points than branched chain alkanes?

linear versus branched —> higher melting/boiling points due to better stacking and surface area contact.

Why do alkanes have higher boiling points than alkenes?

With 109.5 degree bond angles in alkanes, the carbon atoms are not in a straight line and therefore the molecules are a little farther apart. The alkynes on the other hand, can approach each other more closely and therefore have slightly greater attraction, and a slightly greater boiling point.

What is the difference between a straight chain and branched chain alkane?

The key difference between straight and branched chain alkanes is that in straight-chain alkanes, all the carbon atoms bond with each other forming a continuous chain whereas branched-chain alkanes have side chains attached to a continuous carbon chain.

Why branched chain alkanes are more stable than straight chain alkanes?

Branched alkane hydrocarbons are thermodynamically more stable than straight-chain linear alkanes. Because the steric and quantum energy terms cancel, this leaves the electrostatic energy term that favors alkane branching.

Why does increased branching lower boiling point?

Branching decreases the boiling point So the increase of surface area increases the ability of individual molecules to attract each other. Branching in molecules decreases the surface area thereby decreasing the attractive force between individual molecules. As a result, the boiling point decreases.

What is effect of branching on boiling point Why?

Due to decrease in attraction it becomes easier to overcome a molecule, at low temperature we can overcome it, hence the boiling point of an alkane decreases on branching.

Why does boiling point decrease with increase in branching?

Weaker intermolecular forces means that less energy is required to separate the molecules of a compound from its liquid surface, thus lowering the boiling point. As branching increases, the surface area decreases and hence the intermolecular forces of attraction which ultimately results in decrease of boiling point.

Why do alkanes have different boiling points?

There is not a significant electronegativity difference between carbon and hydrogen, thus, there is not any significant bond polarity. The molecules themselves also have very little polarity. Therefore, the boiling points of the alkanes increase with molecular size.