Basification of acid solution. pH calculation. How? This is my first post.

In order to understand basification I've created a pretty simple example as I currently understand it mainly because.. I really don't understand all of it.

Example:

Chemicals = Lye &amp; Vinegar

Reaction  = NaOH + C2H4O2 = H2O + NaC2H3O2

Since the molar ratio of the equation is 1:1...

                Molar Mass          It takes...
Lye     NaOH    39.99710928  = 40   Grams of Lye to NEUTRALIZE,
Acetic  C2H402  60.05196     = 60   Grams of Acetic Acid.
                               *....a Weight Ratio of 2:3


Now to the part I don't understand...

1 liter = 1000 grams


At 5% standard acidity, a liter of vinegar has exactly

1000 Grams x 0.05 = 50   Grams of acetic acid in it.


Thus, at the above calculated Weight Ratio of 2:3...

50 Grams of acetic acid x 2/3 = 33.33   Grams of Lye to NEUTRALIZE,
                                50      Grams of Acetic Acid.
                                *....proportional Weight Ratio of 2:3


So far...

We have neutralized the 50 grams of acetic acid in the solution to pH7.

Question:

What would be the pH of the remainder 950ml of water in the bottle of vinegar? Is it the obvious? pH7?

Is my goal only to neutralize the acetic acid in the solution because the remainder is obviously just water and naturally at a of pH7?
You've made some assumptions that we can deal with, and some that need adjustment.

1) 1 liter of water weighs 1000 grams. Correct. However, 1 liter of 5% acetic acid weighs 1005 grams. No big deal; 1 liter will still contain 50 grams of acetic acid.

2) As the commenter noted, neutralizing the acetic acid gives sodium acetate, a weak base with pH ~9. You can use phenolphthalein as an indicator because it changes color at this pH.

3) The liter of neutralized acid will be homogeneous, so the 50 grams of acid and 33.33 grams of sodium hydroxide will be distributed throughout; any sample of the solution will have the same pH. 

(Although it is interesting to do an acid/base titration with phenolphthalein. As you approach the endpoint, a drop of base will splash red, then fade to colorless. The next drop will splash a larger red cloud, then fade; etc. Finally, you might get a huge red cloud and think you are done, but you are just shy of the last bit of neutralization and the solution turns colorless again. The next drop flashes totally red.  The reason I mention this is that you could say that for those few milliseconds when the solution is partially red and partially colorless, the pH is different in different locations, but this is not a steady state, so you mix it till you can get a repeatable measurement.) 

4) What you measure when you stick a pH meter into the solution is the concentration of the hydrogen ion (hydronium ion) that results from the water molecules reacting with everything else all over the solution. The acetic acid is a reactant in the original solution that increases the hydrogen ion quantity, but the sodium hydroxide reduces it, so you have made a solution of sodium acetate, pH ~9.