[Olympiad] Calculate the pH of a buffer solution that is 0.10 M in NH₃ and 0.20 M in NH₄Cl. (Kb for NH₃ = 1.8 × 10⁻⁵)
- 4.74
- 9.26
- 8.96
- 9.56
📝 Batafsil tushuntirish
pKb = -log(1.8 × 10⁻⁵) = 4.74. pOH = pKb + log([Salt]/[Base]) = 4.74 + log(0.2/0.1) = 4.74 + 0.30 = 5.04.pH = 14 - 5.04 = 8.96.