1. The problem statement, all variables and given/known data So I have prepare a buffer solution of 100 mL with ph of 4.00 .I have to use acetic acid and NaAc (sodium acetate ) to do so . The sum of the concentration of weak acid and its conjugate base is equal to 0.10 M ca + cb = 0.10 M How much volume of acetic acid and NaAc should I use to make buffersolution with ph of 4.00 Pka of acetic acid is = 4.76 Also information given : NaAc (molar weight = 82.08g/mol ) and 100 % m HAc (mw= 60.05) (density = 1.05 ) (100 % m) 2. Relevant equations ph = pka - log (HAc/Ac-) 3. The attempt at a solution I tried solving it but i'm not sure if its correct 4.00 =4.76 - log(HAc)/Ac-) 4.00-4.76 = - log ( Hac/ Ac-) [HAc]/ [Ac-] = 10^0.76 = 5.754 we know ca +cb = 0.10 M x 0.1 L = 0.01 mol nAc- + 5.754 x n Ac- = 0.01 mol 6.754 nAc- = 0.01 mol so nAc- = 0.01/ 6.754 = 0.00148 mol nAc- HAc = 0.01 - 0.00148 =0.008519 mol HAc SO we have to use 0.01 mol of HAc and 0.001480 mol of NaAc HAc c=(100% x 10 x1.05 g/ml)/ 60.05 g/mol = 17.458 M c= n/v 17.458 M= 0.01 mol/ V V= 5.71 x10^-4 L => 0.57 ml We gonna add 0.57 ml of HAc and for NaAc = 0.001480 mol x Mw ( 82.08) = 0.121520 g NaAc Is this correct ??Please explain if its not ??