GKFix MCQ Question

The pH of a 0.005 M codeine solution is 9.95. What is its ionization constant (Kb)?

• A. 1.59 × 10⁻⁶
• B. 8.91 × 10⁻⁵
• C. 7.94 × 10⁻⁹
• D. 3.2 × 10⁻⁷