equivalence point/ equilibrium question?

Question

the concentration of 15 mL of acetic acid diluted to 250 mL of water is 1.048 M.
what volume of 0.0867 M of NaOH is required to reach the equivalence point?

Answer 1

moles of HOAc = 0.250 L x 1.048 M = 0.262 moles
0.0867 M x L = 0.262 moles
3.022 Liters of NaOH

I suspect that you meant you diluted 15 mL of 1.048 M HOAc to 250 mL and then titrated with NaOH. If so, then-
0.015 L x 1.048 M = 0.01572 moles HOAc
0.0867 M x L = 0.01572 moles
L = 0.181 L or 181.3 mL

Answer 2

You can work this out, and will probably learn more, by thinking it through without a formula.

The wording of the first sentence is a bit unclear, but I assume it means that you took 15 mL acid, diluted it to A TOTAL OF 250 mL, and then titrated the whole 250 mL against NaOH. If I got that wrong, you will just need to change the numbers in what follows.

250 mL x 1.048 mol/L = (you do the arithmetic) mmol acid.

Since acetic acid is monoprotic, you need just that number mmol NaOH.

0.0867 mol/L NaOH x required volume (mL) = mmol NaOH, which you just found out.

Answer 3

Is this a Chemistry Homework/Lab assignment? It looks like you did a titration just now. Write out your givens, place them into your formula (make sure you fix everything so that Coefficients are correct and stuff) and solve for your unknown.