IEB Grade 12 Organic chemistry notes

organic molecules molecules carbon atoms
containing
-




-




>
study of compounds which
mainly contain carbon and hydrogen


Unique chemistry of carbon
> can form 4 covalent bonds in excited state

>
undergoes hybridization (Corben having valency of 4)
>
carbon atoms bond with other carbon atoms to form long chains ( catenation )
/ tribe bonds
single / double
>




Important features of carbon
1. Carbon can exist as different allotropes (different crystalline structures of the same element)

different arrangements leads to substances having different properties
-




2. Carbon will form 4 bonds in
organic chemistry
3. The process of hybridization :



Ground state addition of a small
> Excited state

Zp of Zp
amount
energy
25 25


IS IS

H


H C H
1. Representation
a) Structural formulae : all the bonds and atoms
H

b) Semi structural formulae
-
: all the bonds CH ,
-


CH z CHZ CH }

c) Condensed structural formulae double It ripple bonds CH} CH CHCH }
only
:



d) Shortened condensed structural formulae double It ripple bonds (
only repeating components
:




of the compound are shown in brackets ) ( Hs kHz )zCH}
e) Molecular formulae : number and types of atoms Catto

, hydrocarbon -



compound containing only carbon and hydrogen atoms

functional group -

an atom / group of atoms that form the centre of chemical activity
in the molecule




2. Classification ( homologous series )

>
a series of similar compounds which have the same functional group and
have the same general formula ,
in which each member differs from the

previous one by a
single CHZ Unit




§ !,§§^§e§ }
halo alkanes
-




hydrocarbons alcohols
'




, -


carboxylic acid
•
esters

Alkanes (non-polar )
>
Swat hydrocarbons (single bonds between carbon atoms)

>
weak intermolecular forces
'

methane / ethane / / butane are at temperature
propane gasses room


pentane / hexane / heptane / octane / nonane / decane
-

are
liquids at room temperature
+12 carbons
-

are solids at room temperature
>
general formula
:
Cn Hantz functional group : saturated hydrocarbons

Alkenes

Unsaturated ( double bond ) H H
hydrocarbons
>




(important Comercial organic chemical and polythene ) H C C H
:
> ethene makes
simplest alkene
>
general formula
:
Cn Hzn

Hzc CH CH z CH }


But 1- ene
carbon carbon bond
functional group double
-


: -




Alkynes
Unsaturated ( triple bond )
hydrocarbons
>



C C H
>
ethyne (simplest alkyne ) H

>
general formula
:
Cn Hzn -2

HC C CH , CH }

But -

l -




yne