Energy is released while b. mixing the solute and solvent particles
Explanation:
Solute is a component in the solution that is present in lesser quantity.
Solvent is a component present in larger quantity in the solution. It is the one that dissolves any substance within it (the solute).
In any reaction when energy is released then it is termed as exothermic reaction.
In a reaction when energy is absorbed then it is termed as endothermic reaction.
When we separate solute and solvent in a solution , energy is required so it is endothermic. But while doing the reverse, that is, while mixing solute and solvent, energy is released.