4
Carbon and its Compounds
IMPORTANT NOTES
9. Unsaturated organic compounds : Organic compounds in which a double or a triple bond exists between two carbon atoms in a carbon chain, are called unsaturated organic compounds. 10. Hydrocarbons : Organic compounds which contain only carbon and hydrogen atoms are called hydrocarbons. 11. Straight chain hydrocarbons : Hydrocarbons, in which all the carbon atoms are linked to one another in a straight chain by a single covalent bond are called straight chain hydrocarbons. 12. Branched chain hydrocarbons : Hydrocarbons, in which one or more carbon atoms are attached to the main straight chain of carbon atoms by a single covalent bond are called branched chain hydrocarbons. 13. Isomerism : The phenomenon due to which there can exist two or more organic compounds, with different physical and chemical properties, due to the difference in arrangement of carbon atoms in their structure, but have same chemical formula is called isomerism. 14. Homologous series : A group of members of the same class of organic compounds, which differ from each other by a – CH2 group, when arranged in the ascending order of molecular mass, is called a homologous series. 15. Homologous : The members of the same class of organic compounds, when arranged in the ascending order of molecular mass, such that they differ by 14 amu or a – CH2 group are called homologous. 16. Alkanes (saturated hydrocarbons) : Compounds of carbon and hydrogen, in which all the valencies of carbon atoms are satisfied by single covalent bonds are called saturated hydrocarbons or alkanes.
1. Covalent bond or Molecular bond or Homopolar bond : A chemical bond formed between two non-metallic elements by the mutual sharing of one or more electron pairs is called covalent bond. 2. Covalency : The number of electron pairs which an atom of an element mutually shares with another atom or atoms of the same or different elements, so