Kamis, 25 Mei 2017

A chemical learning video about the difference in the number of bonds between alkanes and alkenes

Differenrate The Number Of Bond  Between Of Alkanes And Alkenes


1. Alkanes
Alkane compounds are the simplest carbon chains. Alkanes are saturated hydrocarbon compounds because they have a single bond. General formula of alkanes CnH2n + 2. The simplest compound of alkanes is methane. Methane has only one carbon atom binding four H atoms. The following table presents the first straight chain alkana data. Based on the table in front can be seen that the difference of the above ten compounds lies in the number of methylene groups (- CH2 -). Compounds with such conditions are called homologous. The composition of the compound is made such that the difference with its near neighbor is only at the number of methylene called the homologous series.

a.       Names of alkanes
The alkana naming follows the IUPAC system, which is a nomenclature system based on the idea that the structure of an organic compound can be used to derive its name and vice versa, that a unique structure can be drawn for each name.nBasic IUPAC system is a straight chain alkane.
1) Alkanes straight chain (not branched)
The straight chain alkanes are named according to the number of carbon atoms as listed in the table above. Sometimes it is added normally (n) in front of the alkana name.

2) Cyclic alkanes (closed chain)
Cyclical (closed) cyclic alkanes are named by the number of carbon atoms in the ring, with the addition of cyclo-prefixes.

3) Branched alkanes (have side chains)
Alkane compounds sometimes bind to other elements of one or more carbon atoms. Other elements in the alkane chain are called substituents. The type of alkane substituent that is often encountered is the alkyl group. The alkyl group is an alkane that loses 1 H atom. The equation is the same as alkanes, only the ending is changed to -il. The formula is generally CnH2n + 1. The following table presents the series of alkyl groups.
If the alkane has a side chain then the naming follows the rules as follows.
1. The longest chain is the main chain.
2. The main chain is numbered starting from the end of the chain having substituents.
3. Order sequence name: branch number, branch name, name of the main chain alkana.
4. If there is a methyl group on atom C number 2, the alkane name is prefixed with iso.
5. If the alkane has the same branch more than one, the branch name is combined into one and given the prefix di- (number of branches are two), tri- (number of branches is 3), tetra- (number of branches is four).
6. If alkanes have different branches, name writing is sorted in alphabetical order.
b.  Isomer alkanes
The isomer is a compound having the same molecular formula, but the structure formula is different. The lowest alkane compound which can have isomers is butane (C4 H10).
c. The properties of alkanes
1) Physical properties
1. Alkanes are nonpolar compounds.
2. The alkanes of a straight chain at room temperature vary.
3. The higher the number of carbon atoms, the higher the boiling point.
4. The existence of a branch chain on alkane compounds decreases its boiling point.
5. Soluble in nonpolar solvents (CCl4) or slightly polar (diethyl ether or benzene) and insoluble in water.
6. Alkane lighter than water.
2) Chemical properties
1. Alkanes and cycloalkanes are not reactive, quite stable when compared with other organic compounds. Because less reactive, alkanes are sometimes called paraffins (derived from Latin: parum affins, which means "very small affinities").
2. Alkanes can react with halogens, one of the H atoms replaced by a halogen. The reaction with the halogen is called a halogenated reaction and produces an alkyl halide.
Example: CH4 + Cl 2 → CH3 Cl + HCl
3. Alkanes can be completely burned to produce CO2 and H2O.
Example: CH4 + 2O2 → CO2 + 2H2O
2. Alkene
Alkene is an unsaturated hydrocarbon compound with a double bond (-C = C-). The simplest alkene is ethene, C2H4. The general formula of C2H2n alkenes. The following table presents the homologous series of alkenes.

a.       The name of the alkenes
1) straight chain alkene
Duplicated carbon atoms (C = C) are numbered indicating the double bond. Numbering starts from the end of the chain closest to the double bond.
2) Alkene with branching chains
1. The main chain is the longest chain and contains double bonds.
2. The main chain numbering starts from the closest to the double bond, not the nearest branch.
3. Order sequence name: branch number, branch name, double bond number, name of alkenes.
3) Alkene with more than one double bond
If the alkene has more than one double bond, its name is given an additional diene (for two double bonds) or trienes (for three double bonds).
b. Alkaline isomers
The lowest alkene having the isomer is butene (C4H8). Alkene has two types of isomers as follows.
1) Isomer position
Position isomers are compounds of the same molecular formula, but have different atomic arrangements. Alkanes have only one type of position isomer, but alkene has two types of atomic arrangement changes:
1. Positional isomers in which position changes are experienced by double bonds,
2. position isomers in which position changes are experienced by the branch chain.
2) Geometric isomers
Geometric isomers make double bonds as axes. The geometrical isomeric condition of a double bonded C atom must bind two different atomic groups.
c. Alkene properties
  1) Physical properties
Alkene has the same physical properties as alkanes. The difference is that alkene is slightly soluble in water. This is due to the existence of the double bond forming the bond S. The S bond will be withdrawn by hydrogen from partially charged water.
2) Chemical Properties
a) Oxidation
As with most hydrocarbons, alkene burning / oxidation will also produce CO2 and H2O.
b) Addition of H2
The adduct reaction is a double bond termination reaction. In the addition of alkenes, the double bond is transformed into a single bond.
c) Addition of halogens (F2, Br2, I2)
The adduct reaction by halogens will break the multilayered chain of alkenes forming alkanes. Furthermore the halogen will become the branch / substituent of the alkane formed
c) Addition of acid halides
Addition with the halide acid will break the double bond on alkenes to alkanes following the Markovnikof rule. The H atom of the acid halide will be attached to the carbon atom of the unsymmetrical alkene having the largest H atom. If the double-bonded C atom has the same amount of H, the halide will be attached to the longest C atom. CH3 CH = CHCH3 → double bonds divide equal number of C atoms and symmetrical H → atoms CH3CH 2CH = CH2 → double bond does not divide as much as C and H → asymmetry

The difference between alkanes and alkenes is
·         Alkanes are saturated hydrocarbons which means they are compounds with a single bond between the atoms The alkenes are unsaturated hydrocarbons which means they are compounds with one or more double bonds / one or more triple bonds between the carbon atoms.
·         Alkanes are stable hydrocarbons because carbon bonds are difficult to solve
·         Alkena less satbil from alkana.
·         Alkanes are also called paraffins.

·         Alkene is also called olefin.


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10 komentar:

  1. Why Alkanes and cycloalkanes are not reactive?

    BalasHapus
    Balasan
    1. Alkana and cyclo alkanes are less reactive these things that do not have double bonds, so binding saturation and can not be reaksikan lagi.Keyaktifan kimiawai Alkana Alkana contain a strong single C-C bond and strong C-H bonds. The C-H bond has a very low polarity because there are no molecules that carry significant positive or negative ions to attract other molecules. By it alkanes have a fairly limited reaction. Some things that can be done on alkanes: alkanes can be burned, this destroys all the molecules; Alkanes can be reacted with several halogenendules of C-H bonds; Alkanes can be broken down, with a bonding bond C-C. The reaction Sicoalkanes have reactivity very similar to alkanes, except for very small cycloalkanes - especially cyclopropane. Cyclopropane is much more reactive than you might think. The reason is because of the bond angles in the ring. Normally, carbon carbon forms four single bonds, the bond angles are about 109.5 °. At this cyclopropane is 60 °. With adjacent electron pairs, there is resistance to rejection between electron pairs that connect carbon atoms. This makes the bonds easier to break.

      Hapus
  2. What if alkanes and alkenes react with metals ?

    BalasHapus
    Balasan
    1. One form of alkane compound can be reacted with the metal is an alkane compound can react with Mg metal to form a grignard sennyawa

      Hapus
  3. Explain why alkene is less stable than alkanes? And why is alkane called paraffin?

    BalasHapus
    Balasan
    1. The alkenes are unsaturated hydrocarbons which means they are compounds with one or more double bonds between the carbon atoms. The particular alkene is those unsaturated hydrocarbons that have at least one double bond. They are represented by the chemical formula CnH2n in general when there are no other functional groups. They are also called olefins. Alkene has pi bonds between carbon atoms, and when subjected to a lot of reactions breaking pi bonds in order to form a single bond so that they are more reactive than alkanes but less stable than alkanes.
      Alkanes are called paraffins because alkanes are hydrocarbons whose C chain consists only of a single covalent bond. Often referred to as saturated hydrocarbons, because the number of Hydrogen atoms in each molecule is maximized.
      The main characteristic of the alkane that distinguishes it from other carbon-hydrogen compounds is the saturated alkane. Because it is saturated, the alkana compound does not contain double bonds between the carbon atoms. The compound having a double bond will be highly reactive.

      Hapus
  4. What is the use of alkanes and alkenes?

    BalasHapus
    Balasan
    1. In general, alkanes are useful as fuel and raw materials in the petrochemical industry.
      Methane; Useful as fuel for cooking, and chemical raw materials such as H2 and NH3.
      Ethane; Useful as a fuel for cooking and as a refrigerant in a two-stage cooling system for low temperatures.
      Propane; Is the main component of LPG gas for cooking and raw materials of organic compounds.
      Butane; Useful as vehicle fuel and synthesis rubber raw materials.
      Octana; Is the main component of motor vehicle fuel, that is gasoline.
      Use of Alkene
      Etena; Used as raw material for making polythene plastic (PE).
      Propene, used to make plastics Some uses of monomers and polymers, ie polymers for making synthetic fibers and cooking utensils.

      Hapus
  5. Please specify what kind of substituent alkanes?

    BalasHapus
    Balasan
    1. In the substitution reaction there is a change or exchange of an atom / atomic group by
      Atoms or other clusters.
      CH4 + Cl2  CH3Cl + HCl methyl chloride
                                                     (Chloromethane)
      CH3Cl + Cl2  CH2Cl2 + HCl methyl dichloride
                                                      (Dichloromethane)
      CH2Cl2 + Cl2  CHCl 3 + HCl methyl trichloride
                                                      (Trichloromethane)
      CHCl3 + Cl2  CCl4 + HCl carbon tetrachloride
                                                     (Tetrachloromethane)
      CnH2n + 2 + X2 → CnH2n + 1X + HX

      Hapus

A chemical learning video about the difference in the number of bonds between alkanes and alkenes

Differenrate The Number Of Bond  Between Of Alkanes And Alkenes 1. Alkanes Alkane compounds are the simplest carbon chains. Alkane...