Which of the following has the highest hydroxyl ion concentration?

Which of the following has the highest hydroxyl ion concentration?

A. HCl

B. NH4OH

C. HNO3

D. NaOH

The correct answer is:

D. NaOH

Explanation:
Sodium hydroxide (NaOH) is a strong base and dissociates completely in water to produce a high concentration of hydroxyl ions (OH⁻).

HCl and HNO₃ are strong acids (high H⁺, very low OH⁻), while NH₄OH is a weak base and produces fewer hydroxyl ions than NaOH.

PQN: 2