"AKC SCIENCE CLASSES"
CLASS 10 TH (CBSE AND MP BOARD)
CHAPTER 04
CARBON AND ITS COMPOUNDS
BASIC CONCEPTS
1). Carbon is tetravalent and combines with carbon and atoms of other elements like hydrogen, oxygen, nitrogen, chlorine, and sulphur by sharing of electrons. The bonds formed are called covalent bonds. This property of carbon to form bonds with other carbon atoms giving rise to large molecules is called catenation.
2). Carbon can exist in two or more forms in the same state, i.e., it exhibits phenomenon of allotropy, e.g., carbon form graphite and diamond.
3). Compounds containing carbon and hydrogen are called hydrocarbons. Compounds with formula CnH2n+2 are called saturated hydrocarbons. Those with lesser number of hydrogen atoms per carbon atoms are called unsaturated hydrogens.
4). Compounds that contain the same molecular formula but different structures are called isomers, e.g., n-butane (C5H12) and isobutane (C5H12).
5). Groups like --Cl (chloro), --OH (hydroxy), --COOH (carboxylic acid), --CHO (aldehyde) etc., are called functional groups. The functional group. The functional group is attached to the carbon chain by replacing hydrogen atom or atoms. Compounds having similar functional groups show similar chemical properties.
6). The ability of carbon atom to be linked to form chains of varying lengths gives rise to homologous series of compounds in which same functional group is attached to carbon chains of different lengths.
7). Carbon compounds burns in air with emission of heat and light. Thus most of the fuels that we use are either carbon or its compounds.
8). Carbon compounds like ethanol and ethanoic acid find extensive use in our daily life.
9). Soaps are molecules of sodium or potassium salts of long chain carboxylic acids. Synthetic detergents are sulphonates of hydrocarbons obtained from petroleum.
10). In saturated hydrocarbons, each carbon atoms is attached to four other atoms with single covalent bond. These are also called alkanes. Unsaturated hydrocarbons contain either a carbon-carbon double bond (C=C) or carbon-carbon triple bond (C≡C) in their molecules. These are called alkenes and alkynes respectively. An alkene contains 2 hydrogen atoms less and an alkyne 4 hydrogen atoms less than the corresponding alkane. Similarly carbon forms single covalent bond or double covalent bond with other atoms, e.g., carbon tetrachloride
12). Saturated hydrocarbons give substitution products wherein an atom or a group present in saturated compound is replaced by another atom or group. Unsaturated hydro-carbons give addition products in which an atoms or group of atoms are added up.
13). Fermentation is a slow process of breaking down of organic compounds by micro-organisms to simpler molecules at 20-30℃. Ethyl alcohol is obtained from sugarcane by fermentation.
