Question

The energy change for the reaction between hydrochloric acid and sodium hydroxide is -56 kJ/mol. Therefore....

a. the reaction is exothermic and the temperature increases

b. the reaction is exothermic and the temperature falls

c. the reaction is endothermic and the temperature rises

d. the reaction is endothermic and the temperature falls

Answer 1

Solution:

HCl(aq) + NaOH(aq) → NaCl(aq) + H₂O(l), ΔH = -56 kJ/mol.

It is neutrilisation reaction and neutrilisation reactions are exothermic (ΔH < 0).

Therefore,

a. the reaction is exothermic and the temperature increases