Answer: The reaction is exothermic in nature.
Step-by-step explanation:
Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and
for the reaction comes out to be negative. The reaction mixture becomes warm.
Endothermic reactions are defined as the reactions in which energy of the product is greater than the energy of the reactants. The total energy is absorbed in the form of heat and
for the reaction comes out to be positive.The reaction mixture becomes cold.
When hydrochloric acid and sodium hydroxide are mixed, the mixture becomes warm and thus it can be concluded that the reaction is exothermic in nature.