CHEMICAL REACTIONS AND EQUATIONS BY NSA VARSHINI 10D 17
by Varshini N
1. CHARECTERISTICS OF CHEMICAL CHANGES
1.1. CHANGE IN COLOR
1.2. CHANGE IN STATE
1.3. EVOLUTION OF GASSES
1.4. FORMATION OF PRECIPITATE
1.5. CHANGE IN TMPERATURE
2. TYPES OF REACTIONS
2.1. BASED ON HEAT EXCHANGE
2.1.1. EXOTHERMIC Heat energy is released, bonds are made
2.1.2. ENDOTHERMIC Heat energy is absorbed, bonds are made
2.2. BASED ON REACTANTS AND PRODUCTS
2.2.1. 1) COMBINATION two or more reactants form a single product
2.2.2. 2) DECOMPOSITION One reactant breaks down into 2 or more products
2.2.3. 3) DISPLACEMENT An element displaces a less active element
2.2.4. 4) DOUBLE DISPLACEMENT Two aqueous salts exchange their cations and anions to form two new salts
3. COMMON CHEMICAL PHENOMENON
3.1. RANCIDITY
3.2. Oxidation of fat containing food, prevented by anti oxidants
3.3. CORROSION
3.3.1. Oxidation of metals in presence of air and moisture. Can be prevented by painting , greasing or galvination