Question

If an exothermic chemical reaction occurs, the surroundings become warmer. Where does this energy come from?

Answer 1

Step-by-step explanation:

An exothermic chemical reaction is defined as reaction in which energy is released as a product into a surrounding. Increase in temperature of the surrounding is also observed.

The energy in the exothermic chemical reaction is due to formation of products which are more stable than the reactants. During the chemical reaction breaking and formation of bonds takes place which leads to formation of stable products.

These so formed products are stable at lower energy due to which excessive energy is released out as a heat into surrounding.

An endothermic chemical reaction is defined as reaction in which energy is absorbed from the surrounding. Decrease in temperature of the surrounding is also observed.

Answer 2

It comes to from the chemical reaction itself. Exothermic reaction release heat because the energy level of the products is lower than that of the reactants. Therefore, the net enthalpy change of the reaction is negative (-), meaning heat or light (or any other form of energy) is released into the environment. An example of an exothermic reaction is the combustion of fuel.