V.C.E Chemistry

Year 11 Revision Notes

Organic Chemistry

Organic Chemistry

Naming Organic Compounds

Alkanes        C_nH_2n+2

Alkenes        C_nH_2n

Alkenes – with one substitution

Alkynes        C_nH_2n-2

Alkynes with One Substitution

Cyclic Compounds

Benzene With One Substitution

Functional Groups

Alcohols

Amines

Carboxylic Acids

Aldehydes

Organic Chemistry

Organic chemistry is the chemistry of the compounds of carbon.

The misleading term “organic” is a relic of the days when chemical compounds were divided into two classes, inorganic and organic, depending upon where they had come from. Inorganic compounds were those obtained from minerals whereas organic compounds were those obtained from vegetable or animal sources, that is, from material produced by living organisms. Indeed, until about 1850 many chemists believed that organic compounds must have their origins in living organisms, and consequently could never be synthesised from inorganic material.

These compounds from organic sources had this in common, they all contained the element carbon. Even after it had become clear that these compounds do not have to come from living sources but could be made in the laboratory, it was convenient to keep the name organic to describe them and compounds like them. The division between inorganic and organic compounds has been retained to this day.

Today, although many compounds of carbon are still most conveniently isolated from plant and animal sources, most of them are synthesised. They are sometimes synthesised from inorganic substances like carbonates or cyanides, but more often from other organic compounds. There are two large reservoirs of organic material from which simple organic compounds can be obtained, petroleum and coal. Both of these organic in the old sense, being products of the decay of plants and animals. These simple compounds are used as the building blocks from which larger and more complicated compounds can be made.

What is so special about the compounds of carbon that they should be studied separately from the compounds of all the other one hundred odd elements of the Periodic Table?. In part, at least, because there are so many compounds of carbon, and the compounds of carbon can be so large and complex.

The number of compounds that contain carbon is many times greater than the number of compounds that do not contain carbon. These organic compounds have been divided into families, which generally have no counterparts among inorganic compounds.

Organic compounds containing thousands of atoms are known, and the arrangement of atoms in even relatively small molecules can be very complicated. On of the major problems in organic chemistry is to find out how the atoms are arranged in molecules, that is, determine the structures of compounds.

There are many ways in which these complicated molecules can break apart, or rearrange themselves, to form new compounds and also there are many ways in which atoms can be added to these molecules, or new atoms substituted for old ones. Much or organic chemistry is devoted to find out what these reactions are, how they take place, and how they can be used to synthesise compounds we want.

What is so special about carbon that it should form so many compounds?. Carbon atoms can attach themselves to one another to an extent not possible for atoms of any other element. Carbon atoms can form chains thousands of atoms long, or rings of all sizes and the chains and rings can have branches and cross links. These carbon atoms in the rings and chains can have atoms of other elements attached to them, mainly these are Hydrogen (H), but can also be Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I), Oxygen (O), Nitrogen (N), Sulphur (S) amongst others.

Each different arrangement of atoms corresponds to a different compound, and each compound has its own characteristic set of chemical and physical properties. Organic chemistry is a field of immense importance to technology, it is, for instance, involved in the chemistry of dyes and drugs, paper and ink, paints and plastics, petrol and rubber tyres as well as the food we eat and the clothes we wear.

Naming Organic Compounds

Alkanes         C_nH_2n+2

Methane           CH₄

Ethane  CH₃ – CH₃       (C₂H₆)

Propane           CH₃ – CH₂ – CH₃        (C₃H₈)

Butane  CH₃ – CH₂– CH₂ – CH₃          (C₄H₁₀)

Pentane            CH₃ – CH₂ – CH₂ – CH₂ – CH₃           (C₅H₁₂)

Hexane CH₃ – CH₂ – CH₂  – CH₂ – CH₂ – CH₃            (C₆H₁₄)

Alkanes with One Substitution

Bromomethane CH₃ – Br

Chloromethane CH₃ – Cl

Fluoromethane  CH₃ – F

Iodomethane    CH₃ – I

1-chloro-pentane          CH₃ – CH₂ – CH₂ – CH₂ – CH₂– Cl 

2-chloro-pentane          CH₃ – CH₂ – CH₂ – CH – CH₃ 

                                                                   Cl

3-chloro-pentane          CH₃ – CH₂ – CH – CH₂ – CH₃ 

                                                        Cl

Alkenes         C_nH_2n

Ethene  CH₂ = CH₂      (C₂H₄)

1-Propene        CH₃ – CH = CH₂         (C₃H₆)

1-Butene          CH₃ – CH₂ – CH = CH₂          (C₄H₈)

1-Pentene         CH₃ – CH₂ – CH₂ – CH = CH₂            (C₅H₁₀)

1-Hexene         CH₃ – CH₂ – CH₂ – CH₂ – CH = CH₂             (C₆H₁₂)

2-Pentene         CH₃ – CH₂– CH = CH – CH₃              (C₅H₁₀)

3-Hexene         CH₃ – CH₂– CH  = CH – CH₂ – CH₃  (C₆H₁₂)

Alkenes – with one substitution

Chloro- Ethene CH₂ = CH – Cl

Bromo- Ethene CH₂ = CH – Br

Alkynes         C_nH_2n-2

Ethyne  CH º CH         (C₂H₂)

Propyne           CH₃ – C º CH (C₃H₄)

1 – Butyne        CH₃ – CH₂ –  C º CH (C₄H₆)

1 – Pentyne      CH₃ – CH₂ –  CH₂ –  C º CH  (C₅H₈)

1 – Hexyne       CH₃ – CH₂ –  CH₂ –  CH₂ –  C º CH  (C₆H₁₀)

2 – Hexyne       CH₃ – CH₂ –  CH₂ –  C º C – CH₃

3 – Hexyne       CH₃ – CH₂ –  C  º C –  CH₂ –  CH₃

Alkynes with One Substitution

Chloro ethyne  CH º C Cl

1 –  bromo  Pentyne     CH₃ – CH₂ –  CH₂ –  C º C Br

3 –  bromo  Pentyne  CH₃ – CH₂ –  CH₂ –  C º CH

                                                          Br

Cyclic Compounds

Cyclo hexane

Benzene

Benzene With One Substitution

Benzene  C₆H₆

MethylBenzene  C₆H₅ – CH₃

ChloroBenzene  C₆H₅ – Cl

HydroxyBenzene  C₆H₅ – OH

AminoBenzene  C₆H₅ – NH₂

BenzeneCarboxylic Acid  C₆H₅ – COOH

BenzeneCarboxaldehyde  C₆H₅ – CHO

Functional Groups

– OH          alchohols

– NH₂           amines

– COOH     carboxylic acids

– CHO       aldehydes

– Cl            chloro

– Br            bromo

– F              fluoro

– I               iodo

– R              alkyls   (any alkane, alkene or alkyne)

Alcohols

Methanol          CH₃ – OH         

Ethanol CH₃ – CH₂ – OH         

Propanol          CH₃ – CH₂ – CH₂ – OH         

Butanol CH₃ – CH₂– CH₂ – CH₂ – OH         

Pentanol           CH₃ – CH₂ – CH₂ – CH₂ – CH₂ – OH         

Hexanol            CH₃ – CH₂ – CH₂  – CH₂ – CH₂ – CH₂ – OH            

Amines

Methanamine    CH₃ – NH₂         

Ethanamine       CH₃ – CH₂ – NH₂         

Propanamine    CH₃ – CH₂ – CH₂ – NH₂         

Butanamine       CH₃ – CH₂– CH₂ – CH₂ – NH₂         

Pentanamine     CH₃ – CH₂ – CH₂ – CH₂ – CH₂ – NH₂         

Hexanamine      CH₃ – CH₂ – CH₂  – CH₂ – CH₂ – CH₂ – NH₂         

Carboxylic Acids

Methanoic Acid            H – COOH       

Ethanoic Acid               CH₃ – COOH       

Propanoic Acid            CH₃ – CH₂ – COOH       

Butanoic Acid               CH₃ – CH₂– CH₂ – COOH       

Pentanoic Acid CH₃ – CH₂ – CH₂ – CH₂ – COOH        

Hexanoic Acid  CH₃ – CH₂ – CH₂  – CH₂ – CH₂ – COOH       

Aldehydes

Methanal          H – CHO       

Ethanal CH₃ – CHO       

Propanal           CH₃ – CH₂ – CHO       

Butanal             CH₃ – CH₂– CH₂ – CHO       

Pentanal           CH₃ – CH₂ – CH₂ – CH₂ – CHO       

Hexanal            CH₃ – CH₂ – CH₂  – CH₂ – CH₂ – CHO       

return to Year 11 Revision Index

return to Main Page