Question

What is chemical reactions?? Why respiration is said to be exothermic reaction??​

Answer 1

Answer:

The transformation of chemical substance into a new chemical substance by making and breaking of bonds between different atoms is known as Chemical Reaction.

Respiration is said to be exothermic reaction because exothermic reactions release heat and during respiration also heat is produced along with energy( in the form of ATP) by breakdown of glucose.

HOPE IT HELPS YOU!!!

Answer 2

$\huge\text{\underline{Answer}}$

A Chemical reactions is defined as the reaction in which two or more reactants reacts together to form a new products under some suitable conditions.

Ex:- $\bold{2Mg + O2 => 2MgO}$

Ex:- When a magnesium ribbon is burn in presence of oxygen it forms a grey powder of magnesium oxide.

Every chemical reactions should be balanced to follow the law of conservation of mass.

We can see that a chemical change is accompanied by some factors like :-

1. The evolution of gases.
2. The evolution or absorption of heat energy.
3. The formation of precipitate.
4. Change in colour.

This are some major changes during a chemical reactions.

2) Respiration is considered to be an exothermic reaction because in respiration the glucose is break down in carbon dioxide and water along with release of large amount of energy that is used by cells for metabolic purpose.

Exothermic reaction :- The chemical reactions in which the heat energy is released along with formation of products is called exothermic reactions.

$\bold{C6H12O6 + 6H2O => 6CO2 + 6H2O + 2850 kj }$