ALKANES Flashcards
Definition: Aliphatic
Containing Carbon atoms joined together in straight or branched chains
Definition: Alicyclic
Containing Carbon atoms joined together in a ring that is not aromatic
Definition: Aromatic
Containing one or more benzene rings
Definition: Saturated
Containing only single bonds
Definition: Unsaturated
Containing a multiple carbon-carbon bond
Definition: Homologous group
A series of organic compounds having the same functional group but with each successive member differing by CH2
Definition: A functional group
A group of atoms responsible for the characteristic reactions of a compound
General formula for alkanes
Cn H2n+2
General formula for cycloalkanes
Cn H2n
General formula for alkynes
Cn H2n-2
Definition: Empirical formula
The simplest whole number ratio of atoms of each element present in a compound
Definition: Skeletal formula
A simplified organic formula, with the hydrogen atoms removed from alkyl chains, leaving just a carbon skeleton and associated functional groups
Definition: General formula
The simplest algebraic formula of a member of a homologous series
Definition: Molecular formula
The actual number of atoms of each element in a molecule
Definition: Structural formula
The minimal detail that shows the arrangement of atoms in a molecule
Definition: Displayed formula
The relative positioning of all the atoms in a molecule including the bonds between them
Functional group of aldehyde
CHO
Functional group of ketone
C(CO)C
Functional group of carboxylic acid
COOH
Definition: Structural isomers
Molecules with the same molecular formula but different structure
List the 3 ways structural isomers can occur
- Chain isomers: The hydrocarbon chain may be branched or unbranched
- Position isomers: The hydrocarbon chain stays the same but the functional group is found in different positions along the chain
- Functional group isomers: The functional group is different eg. Alkenes and cycloalkanes
What is the effect of branching on boiling point?
More branching means a lower boiling point because the contact area between molecules is smaller and therefore the London forces are weaker and therefore less energy is required to overcome them.
Why are alkanes relatively unreactive?
Alkanes only contain C-C and C-H bonds which are very strong and therefore hard to break. The are also non-polar so they can attract other species either.
General formula for the complete combustion of a hydrocarbon of formula CxHy
CxHy + (x + 1/4y)O2 -> xCO2 + 1/2yH2O
What condition is needed for an alkane to react with a halogen and what type of reaction is this?
UV light + substitution reaction
Definition: Radical
A radical is a species with a single unpaired electron
Name the 3 stages of free radical substitution
Initiation, Propagation, Termination
Definition: Homolytic fission
The breaking of a covalent bond with one of the bonded electrons going to each atom, forming two radicals
Three limitations of using radical substitution in organic synthesis
- Further substitution can occur
- Substitution at different points in the C chain can happen
- The C chain might double in length
