AS organics Flashcards
homologous series
a series of organic compounds containing the same functional group with sucessive members differing by -CH2
functional groups
a group of atoms responsible for the characteristic reactions of a compound
alkyl group
-CH3
aliphatic
carbon joined to each other branched (straight), unbranched or non-aromatic rings
alicyclic
carbon joined in rings
(with or without branch)
aromatic
some/ all carbons found in a benzene ring
unstaurated
contain C=C or C≡C
structural isomers
same molecular formula but different displayed formulae
What is the naming system for compounds
Nomenclature
Steps to naming organic compounds
- find longest unbranched backbone
- Add suffix for main functional group
- Number the functional groups and/or alkyl side chains
prefix of alcohol
hydroxy-
suffix of aldehyde
-al
suffix of ketone
-one
stems (from 0-10)
- meth-
- eth-
- pro-
- but-
- pent-
- hex-
- hept-
- oct-
- non-
- dec-
Homolytic
Each bonding atoms recieves one electronforming 2 radical
Hetrolytic
One of the bonding atoms recieves both electrons To form a cation and an anion
Radical
a reactive species with an unpaired electron
(but not charged)
Electrophile
(+ve) electron-deficient species , accepts electrons to form covalent bonds
Nucleophile
(-ve)electron-rich species, provides pair of electron to form covalent bonds
General formula of alkanes
CnH2n+2
what is the type of bond in alkanes
sigma bonds
How are sigma bonds formed?
The overlap of the s-orbitals
Why are alkanes non-polared molecules?
- electronegativity diff. between C - H are neglegible
- bonds are relatively non-polared
Structure of alkanes and its bond angles (why?)
Tetrahedral (109.5)
Factors affecting boiling point and (why?)
- Chain length
(↑C = ↑ S.A. = ↑ London forces)
(↑electron = ↑strength of london forces)
2.Branching
↑ branching = ↓ surface contact = ↓ london forces
Why is Alkanes unreactive
- ↑ bond enthalpy of C-C + H-H
- ↓ polarity of sigma bond
What must be present for free-radical substituition
UV light
Three steps of free radical substitution
- initiation
2.propagation
3.termination
Describle initiation of free radical substitution
Halogen molecules broken down in Homolytic fission, under UV
Describle propagation of free radical substitution
- radical attacks alkanes
- C-H bonds Homolytic fission occurs
- alkyl radical formed attacks halogen molecules
- forming haloalkane + halogen radical
Describle termination of free radical substitution
Two radical reacts together to form a single unreactive molecule
3 limitation of free radical substitution
- impurities in the product
- further substitution (when excess halogen under UV)
- substitution on different carbon (cannot control where hetrolytic fission occurs)
Two bonds in alkenes
σ and π
one characteristic of π bond
Fixed above and below the planar, prevent rotation of the molecule
Bond angles of alkene
120 - trigonal planar
How does E/Z isomer work ?
E - piority group on EPPOSITE side of plane
Z- piority group on ZAME side of plane
What is the CIP priority rules ?
- calculate the total atomic no of group
- Group with greatest atomic no is the priority group
4 types of alkene reactions
- hydrogenaton
- Halogenation
- hydrohalogenation
- hydration
what does hydrogenation form
alkane