What is the pH of a buffer made from 0.035 mol of HBrO (Ka= 2.5 x 10-9) and 0.120 mol of KBrO in 1.0 L of solution

Answer 1

Henderson Hasselbalch equation: pH = pKa + log [BrO-] / [HBrO]

pH = ?

pKa = -log Ka = -log 2.5x10-9 = 8.60

[BrO-] = 0.120 M

[HBrO] = 0.035 M

Solving for pH:

pH = 8.60 + log (0.120/0.035)

pH = 8.60 + log 3.43

pH = 8.60 + 0.54

pH = 9.14