Question

You need to prepare an acetate buffer of pH 5.26 from a 0.899M acetic acid solution and a 2.64MKOH solution. If you have 930 mL of the acetic acid solution, how many milliliters of the KOH solution do you need to add to make a buffer of pH 5.26 ? The pKa of acetic acid is 4.76 . Be sure to use appropriate significant figures.

Answer 1

To make an acetate buffer of pH 5.26, you need to calculate the ratio of acetic acid to acetate ions using the Henderson-Hasselbalch equation. Then, determine the volume of KOH solution needed based on the given volume of acetic acid solution. Approximately 911 mL of the KOH solution is required to make the buffer.

Step-by-step explanation:

To prepare an acetate buffer of pH 5.26 from a 0.899M acetic acid solution and a 2.64MKOH solution, you need to calculate the ratio of acetic acid to acetate ions required to achieve the desired pH. The Henderson-Hasselbalch equation is used to determine this ratio:
pH = pKa + log([Acetate]/[Acetic Acid])
Rearranging the equation, we have: [Acetate]/[Acetic Acid] = 10^(pH - pKa)
Now, substitute the given values and calculate the ratio:
[Acetate]/[Acetic Acid] = 10^(5.26 - 4.76) = 1.77828
Since you have 930 mL of the acetic acid solution, you can calculate the volume of KOH solution needed:
Volume of KOH = 930 mL * (1.77828 / (0.899 - 1.77828)) = 911.16 mL
Therefore, you need to add approximately 911 mL of the KOH solution to the acetic acid solution to make a buffer of pH 5.26.