Structural Isomers Flashcards
What is an isomer?
Molecules with the same molecular formula but different structural formula
What is meant by structural isomerism?
Molecules with the same molecular formula, but different structural formula
What are the 3 types of structural isomers?
Chain isomerism
Position isomerism
Functional group isomerism
Structural isomers have ________ chemical properties and _________ physical properties (except functional group isomerism)
Same chemical properties
Different physical properties
What is chain isomerism?
Same molecular formula, but different structural formula…
…caused by different arrangement of the carbon skeleton
Similar chemical properties
Different physical properties
Give an example of a chain isomer of butane
Butane
Methylpropane
Describe why methylpropane is a chain isomer of butane [3 marks]
Both contain the same molecular formula (C₄H₁₀)
Different arrangements of the carbon skeleton - butane has no side branches
Similar chemical properties, different physical properties
What is positional isomerism?
Same molecular formula
Same carbon skeleton
Same functional group…
…but the functional group is in a DIFFERENT position
Similar chemical properties
Different physical properties
Give an example of a positional isomer of pent-1-ene
Pent-1-ene
and
Pent-2-ene
Describe why pent-2-ene is a position isomer of pent-1-ene?
Same carbon skeleton
Same functional group…
…but the functional group is in a different position -
pent-2-ene has a C=C between carbon 2 and 3
pent-1-ene has a C=C between carbon 1 and 2
What is functional group isomerism?
Same molecular formula
Different functional groups
Different chemical properties
Different physical properties
Give an example of a functional group isomer of hex-1-ene
Hex-1-ene
and
Cyclohexane
Alkenes and Cyclohexanes are functional group isomers
Which type of isomer have different chemical and physical properties?
Functional group isomers
What is meant by a homologous series definition?
A group of organic compounds that have the same functional group, but each successive member differs by CH2
