4.1.1: Basic concepts of organic chemistry Flashcards
Hydrocarbon
A compound containing only hydrogen and carbon.
Functional group
An atom or a group of atoms responsible for determining the chemical properties of a molecule.
Homologous series
A series of organic compounds which have the same functional group. Each successive member differs by CH₂
Aromatic molecule
Contain a benzene ring (C₆H₆)
“Arenes”
High degree of unsaturation
Aliphatic molecules
Molecules which do not contain a benzene ring
Empirical formula
Simplest integer ratio of the atoms
e.g. C₂H₅ for C₄H₁₀
Sterioisomerism
Molecules that have the same structural formulae but a different arrangement in 3D.
E/Z isomerism
Substituent groups are arranged differently with respect to the double bond.
• E = “Entgegen”: opposite sides of the double bond
• Z = “Zusammen”: same side of the double bond
How is the double bond split to work out E/Z isomerism?
With a HORIZONTAL line
This fits between the two lines representing the double bond
Optical isomers
Molecules that are mirror images of each other but cannot be superimposed.
Isomers
Molecules with the same kinds and numbers of atoms joined up in different ways.
Structural isomers
Compounds that have the same molecular formula but different structural formulae.
What are the 3 types of structural isomers?
1) Chain
2) Position
3) Functional group
What are ‘chain’ isomers?
Molecules that have different arrangements of their carbon skeleton.
• Chemical properties are the same
• Physical properties are different
What are ‘position’ isomers?
• Same carbon skeleton
• Same functional group, but placed in different position
⟶ Similar chemical properties
⟶ Different physical properties
What are ‘functional group’ isomers?
• Same molecular formulae
• Different functional group
⟶ Different chemical properties
⟶ Different physical properties
General formula for alkanes
C𝒏H2𝒏+2
More branching = ______ boiling point
Lower boiling point
∵ smaller SA for mutual polarisation
Weaker intermolecular forces
Less energy needed to break forces
Alicyclic
An aliphatic compound arranged in non-aromatic rings.
Homolytic fission
When a bond breaks and each bonding atom receives one electron from the bonded pair, forming two radicals.
Heterolytic fission
When a bond breaks and on of the bonding atoms receives both electrons from the pair.
Radical
A species with an unpaired electron.
