Mod 4 organic chem Flashcards
hydrocarbons
compound containing hydrogen and carbon ONLY
Homologous series
family of compounds with similar chemical properties & functional group whose successive members differ by CH2
functional groups
OH - alcohol (ol)
COOH - carboxyllic acid
C=O in middle ketone (one)
C=O at end aldehyde (al)
types of hydrocarbons
aliphatic- straight chain
alicyclic- joined in ring structures
aromatic- some or all atoms found in benzene ring (smell nice)
formulae
empirical- simplist whole number ratio
general - formula for any homologous group eg CnH2n
displayed formula- drawed version showing all Cs&Hs
structural- writing it as you go along CH3CH2CH3
skeletal - lines without including C OR H
Structural isomerism
Compounds with the same molecular formula but different structural formula
-branched
-positional (CH3 going on different carbon)
-functional- make different functional group
eg ketone - aldehyde
Types of bond fission
homolytic- when a covalent bond breaks each of the bonded atoms takes one of the shared bonded pair of electrons from the bond (forms 2 radicals)
heterolytic- when a covalent bond breaks one of the bonded atoms takes both of the electrons from the bond
types of reaction
addition- adding something going from 2 products to 1
elimination- taking something out in a reaction going from 1 to 2 products
substitution- swapping something out for another thing
Alkanes
-sigma bonds
-saturated
-109.5
-CnH2n+2
chain length affect on bp
longer the chain the higher the boiling point
-more london forces
-stronger bonds
-harder to overcome
branching effect on bp
more branching= lower bp
-less surface area of contact
-weaker london forces
easier to overcome
(branches get in the way preventing the branched molecules getting as close together)
reactivity of alkanes
C-C & C-H bonds are strong
C-C bonds are non polar
C-H bonds have similar electronegativities that they are considered non - polar
combustion of alkanes
complete- plentiful oxygen
incomplete- not enough oxygen (carbon monoxide formed) toxic CO
CH4 + O2 –> CO2 + H2O
Free radical substitution
initiation- UV light causes covalent bond to break by homolytic fission
propagation- chain reaction reacts with radical then reacts with compound (BR2)
termination- 3 equations putting all radicals together to make 3 compounds
Alkene to haloalkane
Hydrogen halide addition
H-Br
Alkene to alkane
hydrogenation, adding H2 (nickel catalyst needed)
Alkenes
unsaturated hydrocarbons
-formula = CnH2n
120 degrees shape
sterioisomerism
-Same structural formula but different arrangements of atoms in space
E- egyptian trans
Z- zame zide cis
cis/trans - must have at least 2 hydrogens
Cahn-Ingold-prelog
atom with highest atomic number has priority
compete atoms together then can decide if E/Z isomerism