domingo, 15 de julio de 2012

Amines

Definition: Are organic compounds that contain a nitrogen.
Least organic compounds:
 Primary amine: Methylamine
 Secondary amine: Dimethylamine
 Tertiary amine: Trimethylamine
Functional group:

Primary amine: R-NH2

Secondary amine: R2-NH

Tertiary amine: R3-NH

Esters

Definition: Are organic compounds derived from carboxylic acids. A carboxylic acid contains the -COOH carboxyl group, and in an ester the hydrogen in the group is replaced by a hydrocarbon group of some kind. This could be an alkyl group like methyl or ethyl, or one containing a benzene ring like phenyl.
Least organic compound: Methylmethanoate COOHCH3
Functional group:

O = C - O - R
R   .

Physical properties:
Boiling pointsThe small esters have boiling points which are similar to those of aldehydes and ketones with the same number of carbon atoms.
Molecule
Type
Boiling point
CH3COOCH2CH3
Ester
77,1
CH3CH2CH2COOH
Carboxylic acid
164
Solubility in water
The small esters are fairly soluble in water but solubility falls with chain length.
Molecule
Type
Boiling point
CH3COOCH2CH3
Ester
77,1
CH3CH2CH2COOH
Carboxylic acid
164 


Carboxylic acids

Definition: Are organic compounds containing a carboxyl group attached to it.
Least organic compound: Methanoic acid COOH
Functional group:

R - C = O
O

Physical properties: The boiling points of carboxylic acids of similar size are higher still. The reason for the solubility is that although aldehydes and ketones can't hydrogen bonds with themselves, they can hydrogen bond with water molecules. The carboxylic acids with up to four carbon atoms will mix with water in any proportion.

IUPAC name
Molecular weight
Boiling point
Formula
Butane
58
0
CH3CH3CH2CH3
Propanol
60
97
CH3CH2CH2OH
Ethylmetherether
60
6
CH3-O-CH2CH3
Propanal
58
49
CH3CH2CH=O
Propanoic acid
60
118
CH3CH2COOH




Aldehydes and Ketones

Aldehydes definition: Are compounds containing a carbonyl group with at least one hydrogen attached to it.
Least organic compound: Methanal O=CH2

Ketones definition: Are compounds containing a carbonyl group with two hydrocarbons attached to it.
Least organic compound: Ethanone CH2-CH=O

Structure: They are organic compounds which incorporate a carbonyl group, that is functional, C=O. The carbon atom has two remaining bonds that may be occupied by hydrogen or arkyl or aryl substituents. If, at least one of these is hydrogen, it is an aldehyde. If neither is hydrogen, it is a ketone.

R1    .
 C = O
R2    .

Physical properties: They can H-bond with water, because they have an O atom. The small ones are freely soluble in water, but solubility falls with chain length. The reason for solubility is that although they can't H-bond with themselves, they can with water molecules.

IUPAC name
Molecular weight
Boiling point
Formula
Butane
58
0
CH3CH3CH2CH3
Propanol
60
97
CH3CH2CH2OH
Ethylmetherether
60
6
CH3-O-CH2CH3
Propanal
58
49
CH3CH2CH=O




lunes, 7 de mayo de 2012

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: Cn H2n-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: Cn H2n

 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.