1. The problem statement, all variables and given/known data You have 725 mL of an 0.55 acetic acid solution. What volume (V) of 1.30 M NaOH solution must you add in order to prepare an acetate buffer of pH = 4.99? ( The pKa of acetic acid is 4.76.) 2. Relevant equations pH = pKa + log A/HA Ratio of A- to HA = 10^(pH-pKA) 3. The attempt at a solution - pH = pKa + log A/HA - Ratio A/HA = 10^(pH-pKA) = 10^(4.99-4.76) = 1.70 - Mols of acid = 0.725 mL * 0.55 M = 0.3988 mM - HA = (0.3988 - 1.30 * V) / (0.725 + V) - A- = (1.30 * V) / (0.725 + V) - A-/HA = (1.30 * V) / (0.725 + V) = 0.3988 = (1.30 * V) / (0.725 + V) It has been a while since i've had general chemistry, and now i'm taking biochemistry and need to review acids, buffers, pH, pKa, molarity and volumes. I get to the last step and from here I completely forget what to do. Any help/hints would be appreciated.