What is the molarity of an acetic acid solution if 25.0 mL of 0.212 M NaOH solution is required to neutralize 16.5 mL of the HC2H3O2 solution? HC2H3O2(aq) + NaOH(aq) → H2O(l) + NaC2H3O2(aq)

The molarity of an acetic acid solution : 0.321 M

Titration is a procedure for determining the concentration of a solution by reacting with another solution that is known to be concentrated (usually a standard solution). Determination of the endpoint/equivalence point of the reaction can use indicators according to the appropriate pH range  

Reaction

HC₂H₃O₂(aq) + NaOH(aq) → H₂O(l) + NaC₂H₃O₂(aq)

Molarity NaOh=0.212

volume NaOH=25 ml=0.025 L

mol NaOH =

mol ratio NaOH :  HC₂H₃O₂ from the equation = 1 : 1, so mol HC₂H₃O₂ :

The molarity of acetic acid HC₂H₃O₂ :

Or you can use titration formula :

i think it is true since you can test the answer and can use observations to complete it.