Sodium hydroxide and hydrochloric acid react as shown in this equation.

  (aq) NaOH + (aq) HCl → (aq) NaCl + (l) H2 O

  is a kind of exothermic reaction.

 (ii) By exothermic, we simply mean that heat evolves when the reaction occurs.

  (iii) In exothermic reactions, heat develops in reactions whereas in endothermic reactions heat is given to move the reaction forward.

(iv) In the above reaction, heat will develop so the temperature of the solution will increase in the chemical reaction.