At the equivalence point <em>all HA moles are converted by NaOH</em>. First we <em>calculate how many NaOH moles reacted</em>, using the<em> given concentration and volume</em>:
0.0500 M NaOH * 14.2 mL = 0.71 mmol NaOH
That means that in 4.00 mL of the weak acid solution, there were 0.71 weak acid mmoles. With that in mind we can now <u>calculate the concentration</u>:
The law of the conservation of mass states that matter is neither created nor destroyed, only converted to other forms. Therefore, the mass never changes, even if its appearance does.
