Question

I really don't know how to approach this problem and I really need help.

Using the average molarity of your initial acetic acid solutions, the initial volumes, and the volume of NaOH added to reach the equivalence point, calculate the [C2H3O2-] concentration at the equivalence point.

# of Trials Initial V(HC2H3O2) Vol(NaOH) pH(equiv. Pt.) [OH-] C2H3O2-](eq. Pt.)
Trial 1: 31.1 21.8 7.27 1.86E-007
Trial 2: 30.1 21.7 7.10 1.26E-007
Trial 3: 29.9 24.7 7.13 1.35E-007

Answer 1

I have tried to make sense of this post and can't. It isn't your fault; the problem is that the board doesn't recognize spaces over one(1). You also run into problems if the amount of material covers more than one line. I suggest you do this vertically instead of horizontally. This is really a simpler problem and I can help if we can get the data straight.
Example:
Trial 1
volume acetic acid =
volume NaOH =
etc.
I am a little confused by the following:
initial volume HC2H3O2. Is that what you started with?
How much of this is your calculation versus experimental observation?
I don't get the 1.86E-007, especially the 007 part.