neutralization reaction from lecture (1/30)

[Evelyn-Marian Barber]

In the lecture, the professor mentioned that the neutralization reaction of NaOH + HCl >> NaCl (aq) + H2O (l) had a pH of 7 and was an exothermic reaction. Is this always the case? Will all neutralization reactions be exothermic?

[D Garcia 1C]

Yes, I believe so! :)

[Laura Dinh 1L]

Yes! If you get rid of the spectator ions:

NaOH(aq) + HCl(aq) --> NaCl(aq) + H2O(l)

Na+(aq) + OH-(aq) + H+(aq) + Cl-(aq) --> Na+(aq) + Cl-(aq) + H2O(l)

OH-(aq) + H+(aq) --> H2O(l)

You can see that in the end, you just get the formation of water equation. Since you are forming a covalent bond, the reaction lowers in potential energy and is thus exothermic.

[Madeline Redmond 2A]

Yes, because NaOH is a strong base and HCl is a strong acid, they will both dissociate fully in water. This means that the solution will be neutralized and the pH of neutral water is 7.

[Erin Haisan 1B]

Hello! Yes, generally, all neutralization reactions are exothermic since bonds are being formed, meaning that energy is released by the reaction. Thus, in the reaction NaOH(aq) + HCl(aq) --> NaCl(aq) + H2O(l) the formation of water exhibits more energy than is absorbed. As previously stated, getting rid of the spectator ions leaves the formation of water. I hope this was helpful!

[renee chowdhry 1A]

Hi! Yes, that will always be the case because Na and Cl are disregarded and we have H2O left and the pH of neutral water is 7!