First trial for the titration of acetic acid and naoh

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: First trial for the titration of acetic acid and NaOH. Figure 2: Second derivative curve for Trial 1 of acetic acid and NaOH titration.
Grading Rubric – Weak Acids and Buffers - The pK a of the acetic solution is 4.32. The Henderson-Hasselbach explains the relationship between pK a and pH through the formula pH = pKa + log ([A - ]/[HA]) in which the concentration of the conjugate base is [A - ] and its original acid is [HA]. The half equivalence point can be defined as the point at which the concentration of base is equal to the concentration of acid. Hence, ([A - ]/[HA]) = log 1 = 0, leaving the equation as pH = pK a + 0. In conclusion, at the half-equivalence point, pK a is equivalent to pH and the Henderson-Hasselbach equation supports this. PART A: Preparation and Standardization of NaOH (6 pts) Table 1 : NaOH volumes at the equivalence and half-equivalence points of each acetic acid titration, obtained from the second derivative curves. Trial NaOH volume (mL) at equivalence point NaOH volume (mL) at half-equivalence point pH at half- equivalence point 1 10.18 5.09 4.24 3 A. M. Bohnsack Fall 2018 (revised Z. Baranová) Figure 3 : Second trial for the titration of acetic acid and NaOH. Figure 4: Second derivative curve for Trial 2 of acetic acid and NaOH titration. Figure 5 : Third trial for the titration of acetic acid and NaOH. Figure 6: Second derivative curve for Trial 3 of acetic acid and NaOH titration.
Grading Rubric – Weak Acids and Buffers 2 10.15 5.08 4.32 3 10.75 5.38 4.41 Average 10.36 5.18 4.32 2. (4 pts) Calculate the K a of your acetic acid solution. Discuss this calculation. Based on the value of K a , is acetic acid a strong acid or a weak acid? Why? = .

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