Which pH range describes a weak base?

• A. 0 to 2
• B. 3 to 6
• C. 8 to 11
• D. 12 to 14

Answer: (C)

pH tells how acidic or basic a solution is, and bases raise pH by increasing the amount of hydroxide ions (OH-) or by accepting H+. The strength of a base refers to how completely it dissociates in water. A weak base doesn’t fully ionize, so it makes the solution basic but not extremely alkaline. That gives a pH above 7 but typically in the range of about 8 to 11. Strong bases, like sodium hydroxide, dissociate almost completely and push pH up toward 12–14, while acidic solutions are below 7. So the range 8–11 best describes a weak base.