Chemical reactions and equations

1. Give two daily life examples each for Physical Changes and Chemical Changes.

A. Physical Changes: Wax burning, Water turning into ice.

Chemical Changes: (i) Iron rusting in humid weather, (ii) Milk turning into curd.

2. Mention any Four Characteristics that may associate with Chemical reactions.

A. (i) Change in state,

(ii) Change in colour,

(iii) Evolution of a gas,

(iv) Change in temperature.

3. Give the Examples of the Reactions that involve absorption of heat energy.

A. Absorption of heat energy some common examples are: Melting of ice, Evaporation

of water, Glucose dissolve in water,Boiling of water.

4. Define Reactants.

A. The substance which undergoes bound breaking while taking port in a chemical

reaction is called reactant.

5. Define Chemical Equations.

A. A Symbolic representation of a chemical reaction using formulas and symbols, with

reactants on the left and products on the right.

6. What is the Use of Writing Chemical Equations?

A. Chemical equations are used to represent chemical reactions.

They give information on how substances undergo chemical change and turn into new

products.

They also communicate the conditions required for the reactions to occur as well as the 

quantity of reacting substances products generated.