Answer:
(Incomplete question)
Assuming the molarity of the weak acid is 17.4 M, the answer would be 52.4mL.
Explanation:
Equivalence point is defined as the point where moles of titrant = moles of titrand (analyte).
At equivalence point,
# moles of NaOH = # moles of weak acid
# moles of NaOH = 0.1236 [tex]\frac{mol}{L}[/tex] × 12.43 mL
= 0.1236 mol/L × 0.01242 L
= 0.00153511 moles of NaOH
= 0.00153511 moles of weak acid.
Since the concentration of acid is not stated in your question, we will assume the concentration of the acid to be 17.4 M.
concentration = no. of moles ÷ volume
⇒ vol. = no. of moles ÷ conc.
= 0.00153511 mol ÷ 17.4 mol/L
= 0.0267 L ≈ 26.7 mL
This means that the total volume of the solution at the half equivalence point will be:
26.7 mL + 26.7 ml
= 52.4 mL.
N.B: Confirm missing variable from question: it could be concentration or volume of acid,but it is impossible to have two unknowns. Also, incase its pH of acid that's given, you can solve problem using Henderson-Hasslebauch equation.
