Could someone help with this chem question? I did it and got 25 ml, but i feel like its wrong.

Question

anonymous · Answer

It says to find the volume of 0.20 M NaOH required to adjust the pH of the 0.10 M acetic acid solution to a pka value of acetic acid. I have 50 ml of acetic acid

abb0t · Answer

Can you show me how you got 25 mL?

anonymous · Answer

sure @abb0t

anonymous · Answer

So I know pka =4.76= pH and mole of acetic acid =0.005 mol. The equation become 

HA + NaOH = NaA +H2O

I have HA=0.005 and set NaOH= x and NaA= 0.005-x

anonymous · Answer

$$pH= pka+ \log \frac{ A }{ HA }$$
$$4.76 = 4.76 + \log \frac{ 0.005-x }{ 0.005 }$$$$1 = \frac{ 0.005-x }{ 0.005 }$$

anonymous · Answer

i did it wrong the first time...and now im stuck