Question

Enter your answer in the provided box. How many milliliters of 1.36 M NaOH must be added to 225 mL of 0.20 M NaH2PO4 to make a buffer solution with a pH of 8.10? mL

Answer 1

pH is determined using Henderson-Hasselbalch equation as-

pH =pKa + log [Conjugate Base]/[Acid]

Now, [A] + [B] = 0.045 mol [A] = 0.00513 mol So, [B ] = 0.03987 mal I Now, we have 0.03987 mol of Naoh. X L x 1.36 mol L. Naon = 0.03987 mol of Noon 1 x = – 0.02932 Na oh 0,03987 1.36 .: 293 mL of naon must be added. Pe 1