Alkanes and isomerism Flashcards
What is the general formula of an alkane?
CnH2n+2
What is a hydrocarbon?
A compound/molecule consisting of hydrogen and carbon only
Name the 3 types of structural isomerism
Position
Chain
Functional group
Define structural isomerism
Molecules with the same molecular formula but a different structural formula
Define stereoisomerism
Molecules with the same structural formula but a different spatial arrangement of atoms
What are the types of geometric isomerism?
E and Z
Does geometric isomerism occur in alkenes or alkanes?
Alkenes
In E isomers, where are the largest groups situated around the double bond?
Opposite sides
In Z isomers, where are the largest groups situated around the double bond?
Same side
Why are vdW the strongest intermolecular forces between alkanes?
Alkanes are almost non-polar due to the similar electronegativities of carbon and hydrogen, so no permanent dipole is formed
Explain the trend in the boiling points of alkanes
Boiling point increases as chain length increases because there are stronger vdW forces between molecules due to the greater SA
Why do branched alkanes have a lower bpt than straight chain alkanes?
Smaller SA so weaker vdW forces between molecules
Are alkanes soluble or insoluble?
Why?
Insoluble
Water is held together by hudroghen bonds which are stronger than the vdW forces in alkanes
What type of reactions do alkanes undergo?
Combustion
Will react with haloalkanes
Define molecular formula
The number of atoms of each element in a molecule
