Saturday, 5 October 2013

CARBON AND ITS COMPOUNDS





   Carbon is a unique element which forms more compounds as compared to other elements. It is a non metal which has many other allotropic forms like carbon and graphite.The compounds of carbon are so important that the chemistry of carbon compounds form a separate branch of chemistry called organic chemistry.

                       Covalent bonds

   The compounds containing ionic or electrovalent bonds are called electrovalent or ionic compounds.For ex- NaCl
                           



                                                    but
    
 the bonds formed by sharing of electrons are called covalent compounds.

                               
                             

   Difference b/w ionic and covalent compounds

          Covalent compounds consist of molecules while ionic compounds consist  of ions

          Covalent compounds are liquids or gases at room temp. but ionic compounds are solids
    
          Covalent compounds form weak bonds but ionic compounds form strong compounds.
  
          Covalent compounds low melting and boiling compounds but ionic compounds have high melting and boiling points.
          
            Covalent compounds are generally insoluble in polar solvents and soluble in polar compounds and ionic compounds are vice versa.
            
          Covalent compounds conduct electricity but ionic compounds do not.

                   Unique nature of carbon 

   -Catenation-   the tendency to form bonds with atoms of the same element.
                         strong carbon-carbon atoms are formed
   -Tetravalency- the valency of carbon is four so it can share electrons of                        four other elements or other carbons.
  - Multiple bonds- carbon can form single,double or triple bonds
                       single bond means to share one electron
                        double bond means to share two electrons
                        triple bond means to share three electrons
  

                     HYDROCARBONS

  The organic compounds which consist of only carbon and hydrogen are called hydrocarbons.

               THERE ARE TWO TYPES OF HYDROCARBONS

      -Saturated hydrocarbons- consisting of single bond.They are also  called                      alkanes.
     -Unsaturated hydrocarbons- consisting of double bonds called alkenes
                                                     or
                                   triple bonds called alkynes.
            

                       source-  holyfaith modern abc of chemistry(book)



                      











































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