Question

Energy exchanges take place
1.In the formation of the mixture
2.Formation of solution
3.Formation of compound

Answer 1

During a formation of mixture or a solution or a compound there is a chemical reaction that takes place. As we are familiar with the fact that during formation of a substance energy is released or formed in different forms.

Complete answer:
To answer the question one must be aware of the exothermic and endothermic reactions. In an exothermic reaction, the energy is released in the form of light or heat in the surrounding area. The reason for this release of energy is because the total energy of the products is less than the total energy of the reactants. Therefore the change in enthalpy is always negative.
In an endothermic reaction, energy requires external energy usually in the form of heat for the reaction to proceed. Since this reaction is taking up the energy from the surrounding area, it tends to cool the surrounding area. Here the enthalpy change is positive.
During a chemical reaction the energy is either supplied or released after the formation of the product or when heat or external energy is supplied to cause the reaction. The energy change in a chemical reaction is due to the difference in the amounts of stored chemical energy between the products and the reactants.
All the three options are a type of chemical reaction. As stated earlier, in chemical reactions the energy is released or formed. During the formation of the solution the solute dissolves in the solvent and energy is absorbed and used to break the bond. Once a solution is formed, the energy is released. Similarly during compound formation, bonds of the reactants are broken first and then new bonds are formed. In all three options there is an exchange of energy that takes place.

Note:
Energy is supplied during bond breaking, therefore an endothermic reaction. In the same way energy is released when new bonds are formed, therefore an exothermic reaction. Whether a reaction is exothermic or endothermic depends upon the energy difference between the energy needed to break the bond and the energy released when new bonds form.