To make a buffer solution with a pH, you need to have an equal amount of the weak acid and its conjugate base. In this case, acetic acid (CH3COOH) is the weak acid and its conjugate base is acetate ion (CH3COO-). To calculate how much sodium hydroxide (NaOH) you need to add to form the acetate ion, you need to use the Henderson-Hasselbalch equation. pH = pKa + log([base]/[acid]). For acetic acid, the pKa is 4.76. Using the given values, you can solve for the required amount of NaOH: pH = 4.76 + log([CH3COO-]/[CH3COOH]). Rearranging the equation, you get [CH3COO-]/[CH3COOH] = 10^(pH-pKa) = 0.386. This means you need to add 0.386 moles of NaOH for every mole of acetic acid. To make a 125 ml solution, you need 0.150 moles of acetic acid, so you need 0.058 moles of NaOH or 1.60 ml of 2.75 M NaOH.
To prepare 125 mL of a buffer solution with a desired pH, you need to add an appropriate amount of 2.75 M sodium hydroxide to 0.150 M acetic acid. First, determine the moles of acetic acid present in the 125 mL solution: (0.150 mol/L) x (0.125 L) = 0.01875 mol. Next, use the Henderson-Hasselbalch equation: pH = pKa + log([A-]/[HA]), where A- represents the conjugate base (acetate) and HA represents the weak acid (acetic acid). Find the desired moles of sodium hydroxide needed to achieve the target pH by solving this equation. Finally, calculate the required volume of 2.75 M sodium hydroxide by dividing the moles of sodium hydroxide by its concentration: (moles of NaOH) / (2.75 mol/L).