Question

What type of a reaction occurs when a sodium hydroxide solution is mixed with an acetic acid solution?

A) gas evolution
B) oxidation-reduction
C) acid-base neutralization
D) precipitation

Answer 1

C) acid-base neutralization

Step-by-step explanation:

NaOH + CH₃COOH = CH₃COONa + H₂O

Break the solutions apart:

NaOH = Na⁺ + OH⁻

CH₃COOH = CH₃COO⁻ + H⁺

Combine the resulting solution after the reaction:

OH⁻ + H⁺ = H₂O

Answer 2

C) acid-base neutralization

Step-by-step explanation:

In this type of titration, the equivalence point is at a pH greater than 7, due to weak acid anion hydrolysis, which is a hydrolysis that yields OH - ions.

Example: Titration of acetic acid with sodium hydroxide:

CH3COOH + NaOH→ NaCH3COO + H2O

NaCH3COO → Na+ + CH3COO–

At the equivalence point, all acetic acid was consumed and all NaOH was consumed. However, CH3COO– was produced. - pH is given by the solution of CH3COO - (weak acid anion hydrolysis) - Equivalence point: pH will be greater than 7. Since Na + is an acid-base neutral particle (strong base cation does not hydrolyze), only CH3COO– (weak acid anion) will undergo hydrolysis as shown below:

CH3COO- + H2O → CH3COOH + OH-

OH ions will increase the pH of the solution as they will react with H3O + by the equation:

OH- + H3O+ → 2H2O

We can follow a practical example of the neutralization reaction in our daily lives: in the preparation of a simple lemonade. We know that the lemon has acidity, because it is present citric acid, what to do then to soften the acrid taste in the juice of this fruit? It is necessary to add a base, in this case it is common to use sodium bicarbonate (NaHCO3) to neutralize the acid action and make the lemonade more tasty.