Prabin Kalikote

A chemical reaction in which a single reactant is broken down into two or more products called a decomposition reaction. For example:

CaCO₃ -------> CaO + CO₂
CuCO₃ -------> CuO + CO₂

A chemical reaction in which two or more reactants are combined together to give a single product is called a combination reaction. Examples are:

C + O₂ --------> CO₂
C + 2H₂ ---------> CH₄

A catalyst is a chemical substance that increases or decreases the rate of a chemical reaction without taking part in a chemical reaction.

The +ve catalyst is the chemical substance that increases the rate of a chemical reaction. For example MnO₂. The catalyst is the chemical substance that decreases the rate of a chemical reaction. For example glycerine.

Four factors that bring about a chemical change are:

> Heat                               > Catalyst
> Light                               > Solution
> Pressure ...

Any 4 limitations of balanced chemical eqn are:

1. The physical estate of reactants and products.
2. The concentration of reactants.
3. The rate of the chemical reaction.
4. The time is taken to complete the reaction.

Any three pieces of info that can be obtained from a balanced chemical eqn are:

1. The type of chemical reaction.
2. The name and symbol of reactants and products.
3. The total number of atoms of reactants and products.

A chemical eqn. which contains an equal number of atoms of each element in both reactant and product side is called balanced chemical eqn.

Example: 2H₂ + O₂ --------> 2H₂O