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IB Organic Chemistry Cheat Sheet (DRAFT) by

Organic chemistry. for the predp exam

This is a draft cheat sheet. It is a work in progress and is not finished yet.

Alkanes ♕

Methane
CH4
Ethane
C2H6
Propane
C3H8
and so on...
Alkanes are saturated hydroc­arbons
(only contain C-C bonds)
CnH2n+2

Alkenes

Ethene
C2H4
Propene
C3H6
Unsatu­rated hydroc­arbons since they have at least one C=C double covalent bond
CnH2n

alcohols

The alcohols form a homologous series. The general formula for the alcohols is: CnH2n+1OH
The alcohols’ functional group is –OH. It is respon­sible for the alcohols’ typical reactions. Don’t confuse the –OH group with the hydroxide ion OH-.
Combustion of alcohols -> Alcohols completely combust in the presence of oxygen to form carbon dioxide and water. ethanol + oxygen → carbon dioxide + water
C2H5OH + 3O2 → 2CO2 + 3H2O
They combust incomp­letely when oxygen is scarce, producing water and either carbon monoxide or carbon (soot).
Methanol CH3OH
Ethanol C2H6OH
Propan­-1-ol C3H7OH
  

Combustion of alkanes

Complete combustion
Complete combustion occurs when there is a plentiful supply of oxygen. The carbon and hydrogen atoms react with oxygen in an exothermic reaction. Carbon dioxide and water are produced. The maximum amount of energy is given out.
in general:
hydroc­arbon + oxygen → carbon dioxide + water
example: propane + oxygen → carbon dioxide + water
C3H8 + 5O2 → 3CO2 + 4H2O

Addition reactions of alkenes

Addition reactions occur when one molecule combines with another, forming one large molecule and no other products. The C=C functional group allows alkenes to undergo these reactions.
Example: Ethene reacts with bromine to form 1,2-di­bro­moe­thane:
CH2=CH2 + Br2 → CH2BrCH2Br

Carboxylic acids

The general formula for carboxylic acid is CnH2nO2. The molecular formula is usually written with COOH functional group.
The functional group in the carboxylic acids is the carboxyl group –COOH. It is respon­sible for the carboxylic acids’ typical reactions. They are weak acids – vinegar is a dilute solution of ethanoic acid.
examples
Methanoic acid: HCOOH, Ethanoic acid: CH3COOH, Propanoic acid C2H5COOH, Butanoic acid C3H7COOH
 

more:

Incomplete Combustion

Incomplete combustion occurs when there is a limited supply of oxygen. Carbon (soot), carbon monoxide, and water are produced. Less energy is released, compared to complete combus­tion.

Nomenc­lature