Question

define with examples 1) chemical reaction (2) chemical reaction. (3) exothermic reaction. (4) endothermic reaction. (5) chemical composition reaction (6) chemical decomposition reaction. (7) chemical displacement reaction (8) chemical double displacement relation (9) preapitation reaction (10) oxidation. (11) reduction. (12)redox reaction (12) corrosion (13) rancidity

Answer 1

1.) a reaction is said to be chemical reaction when an object totally lost its initial properties and gain a new property. and in these reactions and object is not able to get back its properties again.

3.) the reactions in which a lot of heat is produced are termed as exothermic reactions.
for example when we add water in calcium oxide it gives calcium hydroxide with a lot of heat this is example of exothermic reaction.

4.) the reactions in which the heat is absorbed are called endothermic reactions for example photosynthesis.

5.) the reactions in which the two simpler reactants during a reaction give only one product I called composition reactions. for example when we take calcium oxide and water it will give only one product that is calcium hydroxide.

6.) the reactions in which a single reactant breaks down to give simple products are called decomposition reactions for example when ferrous sulphate is heated it gives ferrous ferric oxide, Sulphur dioxide and sulphur trioxide.

7.) displacement reactions are those reactions in which a more reactive element displaces less reactive element. for example in zinc + copper sulphate gives zinc sulphate and copper in this reaction with zinc has displaced copper in the reaction.

8.) the reactions in which there is an exchange in ions are called double displacement reactions.

9.) the reactions in which the precipitate is formed or called precipitation reactions these reactions are those reactions in which the insoluble solid crystals are formed.

10.) oxidation reactions are those reactions in which there is addition of oxygen or removal of hydrogen.

11.) reduction reactions are those reactions in which there is an addition of hydrogen or removal of oxygen.

12.) redox reactions and those reactions in which reduction and oxidation take place together.

13.) when a metal is attacked by substances around its such as master acids accept it is said to be crore and this process is called corrosion for example the black coating on silver and the green coating on copper and other examples of corrosion.

14.) rancidity means having foul smell.