Thiols

They are compounds containing an -SH (sulfydryl) group.

Physical properties:
 - Hydrogen bonding is much weaker that that in alcohols.
 - Lower boiling points that similar alcohols.
 - Less soluble in water and other polar solvents than comparable alcohols.
 - Low-molecular-weight thiols stink.
 - Responsible for smells such as those from rotten eggs and sewage the scent of skunks is due primarily to these two thiols.

Chemical properties:
 - 5-Bonds are longer and weaker than those to oxygen.
 - 5-H bonds are non-polar covalent since 5 is less electronegative than O.
 - No hydrogen bonding.
 - Lower boiling points that comparable alcohol.

An example:

   

 Condensed formula: CH₃-CH₂-SH

 IUPAC Name: Ethanethiol

 Common Name: Ethylmercaptan

Ethers

They are organic compounds in which oxygen is bonded to two carbon groups, alkyl groups.

Functional group:                    R-O-R

Physical properties:
 - Ethers have no H atoms bond to the O atom as in alcohols.
 - Therefore molecules in the pure liquid are incapable of hydrogen bonding.
 - Ethers have similar boiling points to alkanes of comparable molecular weigth.
 - Not soluble in water.

Chemical properties:
 - Ethers are flammable.

                                                        CH₃-O-CH₃

            Common name                                                             IUPAC name 

             Dimethylether                                                              Methyoxymethane

Alcohols

They are organic compounds that contain a Hydroxyl group (-OH) attached to a hydrocarbon.
Most of the alcohols are colorless liquids. Methyl alcohols, ethyl alcohol are liquids with fruty odors The higher alcohols those containing 4-10 carbon atoms are somewhat viscous, or oily and tey have hevier fruty odors, some of the highly branched alcohols and many alcohols  containing more than 12 carbon atoms are solid at room temperature.


Physical properties:
 - Most of the alcohol are colorless liquids at room temperature.
 - Methyl alcohol, ethyl alcohol, and isopropyl alcohol are liquids with fruity odors.
 - Alcohol that rank from 4 to 10 carbons are viscous or oily.
 - Some of the highly branched alcohols and many alcohols containing more than 12 carbon atoms.


Chemical properties:
 - Alcohols are flammable. They have a lower boiling point than similar hydrocarbons.

Types of alcohols


 - Primary alcohol
          H                R= radical
      H-C-OH        H= hydrogen
          R

 - Secondary alcohols
         H
     R-C-OH
         R

 - Tertiary alcohols
         R
     R-C-OH
         R

An example:

  

 IUPAC Name: Ethanol

Fractional destillation

Fractional distillation is a process by which petroleum is destillated into fractions, and hydrocarbons in this case, according to each boiling point. In this process, the crude oil is heated so that it vaporizes, separates, and then condenses.

The fractions obtained from crude oil are the following:

Fraction	Composition of carbon chain
Natural gas	Methane, ethane, propane and butane.
Petroleum ether (solvent)	Pentane and hexane.
Naphtha (solvent)	Heptane and octane.
Gasoline	Pentane, hexane, heptane , octane, nonane, decane, undecane and dodecane.
Kerosene	Dodecane, tridecane, tetradecane and pentadecane.
Fuel oils, mineral oils	Pentadecane, hexadecane, heptadecane and octadecane.
Lubricating oil, petroleum jelly greases, paraffin wax, asphalt	Hexadecane, heptadecane, octadecane, nonadecane, heneicosane, dodosane, traicosane and tetracosane.

Engine knock is a sound an engine makes when gasoline ignites too soon because of poor engine timing or the case of law octane fuel. It may cause overheating, loss of power, and engine damage. It occurs in the engine cylinder and often, prior to spark ignition. The sound cames form the vibration of the piston, connecting rod, and leanings.

Stereoisomers

They are molecules in which the atoms are joined in the same order, but the positions are different in space.

Isomers which have their atoms connected in the same sequence but differ in the way the atoms are oriented in space, the difference between two stereoisomers lies only in the three dimensional arrangement of atoms. Stereoisomers can be classed as cis-trans isomers or optical isomers.

Optical isomers

Optical isomers are mirror images of one another. Just as a right-handed glove cannot be superimposed on a left-handed glove, optical isomers cannot be superimposed on one another.

Important terms in organic chemistry

Isomers: They have the same molecular formula but different structure (properties).

    An example:

     

Aromatic Hydrocarbons

They have distinct pleasant aromas. Benzene is the simplest of an aromatic compound. An aromatic compound is an organic compound that contains a benzene ring or another ring in which the bonding is like that of benzene. In a benzene molecule, the bonding electrons between carbon atoms are shared evenly around the ring.

Structure of benzene:

Examples of benzenes:

                IUPAC Name: Methylbenzene

                Common Name: Toluene




     

                 IUPAC Name: 1,2-Dimethylbenzene

                 Common Name: Orto-xylene (O-xylene)

   


                  IUPAC Name: 1,3-Dimethylbenzene

                  Common Name: Meta-xylene (M-xylene)

IUPAC Name: 1,4-Dimethylbenzene

Common Name: Para-xylene (P-xylene)

Cyclic Hydrocarbons

A cyclic hydrocarbon is a compound in which a series of atoms is connected to form a loop or ring.

Examples:

 The first one is cyclohexane.
 The second one is Methylcyclohexane
 The third one is 1,3-Dimethylcyclohexene

Branched Hydrocarbons

To name hydrocarbons, must be done under this rules:

1. Find the longest chain of carbons in the molecule. This chain is considered the parent structure.
2. Number the carbons in the main chain in sequence.
3. Add numbers to the names of the substituent groups to identify their positions on the chain. These numbers become prefixes to the name of the alkyl group.
4. Use prefixes to indicate the appearance of the same groups more than once in the structural formula. Common prefixes are di- (twice), tri- (three times), tetra- (four times), and penta- (five times).
5. List the names of the alkyl substituents in alphabetical order. For porpoises of the alphabetizing, ignore the prefixes di-, tri-, and so on.
6. Use proper punctuation. This is very important in writing the names of organic compounds in the IUPAC system. Commas are used to separate numbers. Hyphens are used to separate numbers and words. The entire name is written without any spaces.

For example:

IUPAC Name: 3-Methylpentane.

Condensed formula: CH₃-CH₂-CH(CH₃)-CH₂-CH₃

Molecular formula: C₆H₁₄

Hydrocarbon's prefixes

Here are the first 100 prefixes, which they can be used in all the types of hydrocarbons.

1 = Meth  2 = Eth  3 = Prop  4 = But  5 = Penta  6 = Hexa  7 = Hepta  8 = Octa  9 = Nona  10 = Dec  11 = Undec  12 = Dodec  13 = Tridec  14 = Tetradec  15 = Pentadec  16 = Hexadec  17 = Heptadec  18 = Octadec  19 = Nonadec  20 = Eicos  21 = Heneicos  22 = Doeicos  23 = Trieicos  24 = Tetracos  25 = Pentacos

26 = Hexacos 27 = Heptacos 28 = Octacos 29 = Nonacos 30 = Triacont 31 = Hentriacont 32 = Dotriacont 33 = Tritriacont 34 = Tetratriacont 35 = Pentatriacont 36 = Hexatriacont 37 = Heptatriacont 38 = Octatriacont 39 = Nonatriacont 40 = Tetracont 41 = Hentetracont 42 = Dotetracont 43 = Triatetracont 44 = Tetratetracont 45 = Pentatetracont 46 = Hexatetracont 47 = Heptatetracont 48 = Octatetracont 49 = Nonatetracont 50 = Pentacont

51 = Henpentacont 52 = Dopentacont 53 = Tripentacont 54 = Tetrapentacont 55 = Pentapentacont 56 = Hexapentacont 57 = Heptapentacont 58 = Octapentacont 59 = Nonapentacont 60 = Hexacont 61 = Henhexacont 62 = Dohexacont 63 = Trihexacont 64 = Tetrahexacont 65 = Pentahexacont 66 = Hexahexacont 67 = Heptahexacont 68 = Octahexacont 69 = Nonahexacont 70 = Heptacont 71 = Henheptacont 72 = Doheptacont 73 = Triheptacont 74 = Tetraheptacont 75 = Pentaheptacont

76 = Hexaheptacont 77 = Heptaheptacont 78 = Octaheptacont 79 = Nonaheptacont 80 = Octacont 81 = Henoctacont 82 = Dooctacont 83 = Trioctacont 84 = Tetraoctacont 85 = Pentaoctacont 86 = Hexaoctacont 87 = Heptoctacont 88 = Octaoctacont 89 = Nonaoctacont 90 = Nonacont 91 = Hennonacont 92 = Dononacont 93 = Trinonacont 94 = Tetranonacont 95 = Pentanonacont 96 = Hexanonacont 97 = Heptanonacont 98 = Octanonacont 99 = Nonanonacont 100 = Hect

Alkynes

Alkynes are chemical compounds which consist only of hydrogen and carbon atoms and are bonded exclusively by triple bonds. 

 Chemical formula: C_n H_2n-2

 Suffix: -yne

 Prefix: Hydrocarbon's prefixes

 Properties:
  - Their melting and boiling points increase with the molar weight.
  - They are less polar.
  - Insoluble in water

 Characteristics:
  - Are unsaturated hydrocarbons.
  - Triple covalent bond.

 Simplest alkane: Ethyne.

Alkenes

Alkenes are chemical compounds which consist only of hydrogen and carbon atoms and are bonded exclusively by double bonds.

 Chemical formula: C_n H_2n

 Suffix: -ene

 Prefix: Hydrocarbon's prefixes

 Properties:
  - Their melting and boiling points increase with the molar weight.
  - They are less dense than water.
  - They are soluble in non-polar solvents or low polarity.

 Characteristics:
  - Are unsaturated hydrocarbons.
  - Double covalent bond.

 Simplest alkane: Ethene.

Alkanes

Alkanes are chemical compounds which consist only of hydrogen and carbon atoms and are bonded exclusively by single bonds.

 Chemical formula: C_n H_2n+2

 Suffix: -ane

 Prefix: Hydrocarbon's prefixes

 Properties:
  - Non-polar molecule.
  - Tent to be gases or liquids.
  - Boil at a low temperature.

 Characteristics:
  - Are saturated hydrocarbons.
  - Simple covalent bond.

 Simplest alkane: Methane.

Main differences between methane and propane:

Methane

Propane

· It is a colorless, odorless gas with a wide distribution in nature. · The main component of natural gas, and probably the most abundant organic compound. · It is lighter than air, so it tends to rise and dissipate into the air, passing less of an explosive risk. · It doesn’t compress as easily. It usually comes to your home from a utility company along dedicated lines to power things like water heater. · Provides less energy per unit volume than does propane. In a given volume, it has 1000 BTUs. · It can be less expensive. · The number of carbon atoms and therefore size of the molecules. CH4. · Its molar mass is 16,04 gmol-1.

· It is a gaseous component of natural gas, component of crude oil. · A mixture of propane and butane is used mainly as vehicle fuel. · It is heavier than air, so it tends to fall to the ground, and pose a greater explosive risk. · It is easy to compress and carry in a portable tank. You can buy compressed propane at most gas stations. It can be used as a barbeque grill. · Provides more energy per unit volume that does methane. In a given volume, it has 2500 BTUs. · It can be more expensive. · The number of carbon atoms and therefore size of the molecules. C3H8. · Its molar mass is 44,1 gmol-1.

Hydrocarbon

Hydrocarbons are organic compounds that have at least one carbon in its composition. They are present in some compounds like carbohydrates, fats and proteins.

Types of hydrocarbons:

1. Alkanes.
2. Alkenes.
3. Alkynes.
4. Cycil hydrocarbons.
5. Aromatic Hydrocarbons

Carbon atom

Carbon is the chemical element with symbol C.

 z = 6

 p+ = 6

 e- = 6

 A = 12

 n. = 6

It has three types of bonds:

 a) Simple bond

            

     

 b) Double bond

 

 c) Triple bond