Question

The graph shows the titration curve for a 12.50-gram sample of vinegar that was titrated with 0.500 M NaOH.

A. What is the pH at the equivalence point?
B. What volume of NaOH was used to reach the equivalence point?
C. How many moles of NaOH is this?
D. Vinegar contains acetic acid (HC2H3O2). What is the mole ratio between acetic acid and NaOH in the neutralization reaction?
E. How many moles of acetic acid are in the vinegar?
F. What is the mass of acetic acid in the vinegar?
G. What percent (by mass) is the acetic acid in the vinegar?

Answer 1

The pH at the equivalence point is approximately 8.72. The volume of NaOH used to reach the equivalence point is approximately 25.00 mL. The number of moles of NaOH used is 0.0125 mol.

Step-by-step explanation:

A. The pH at the equivalence point can be found by determining the pH of the solution when the number of moles of NaOH added is equal to the number of moles of acetic acid present in the vinegar. Based on the titration curve in the graph, we can see that the equivalence point is reached at a pH of approximately 8.72.

B. To find the volume of NaOH used to reach the equivalence point, we can determine the volume on the graph where the pH reaches 8.72. From the graph, it appears that approximately 25.00 mL of NaOH was used.

C. The number of moles of NaOH used can be calculated by multiplying the volume in liters (converted from mL) by the molarity of NaOH. In this case, it would be (25.00 mL / 1000 mL/L) * 0.500 mol/L = 0.0125 mol.