homologous series Flashcards
what is the polarity of hydrocarbons?
non-polar
What intermolecular force is present in alkanes?
only LDF
What is the trend in boiling/melting points of alkanes?
as molar mass of alkanes increases so does the melting point.
Explain the reason for the trend in the boiling/melting point of alkanes.
higher molar mass = more contact surface + greater LDF = increased melting/boiling points
what are the three factors that determine what type of intermolecular force exist between molecules?
- molar mass
- straight-chained or branched structure
- functional group present
Which structure often has a stronger intermolecular force, straight-chained or branched ones?
straight-chained
Why do straight-chained molecules have stronger intermolecular forces than branched ones?
- branches prevent molecules from getting close together = less surface area contact
- Straight allows molecules to get close = more surface area contact
Name two classes that have dipole-dipole forces between their molecules
- aldehydes
- ketones
Name two classes that have hydrogen bonds between their molecules
alcohols, carboxylic acids and amides