A small amount of sodium hydroxide is added to water. When the chemical reaction reaches equilibrium, the pH is 12. Which statement

To analyze the situation:

1. A pH of 12 indicates that the solution is basic. The pH scale is from 0 to 14, where values less than 7 are acidic and values greater than 7 are basic.
2. pH is related to pOH by the equation: \( \text{pH} + \text{pOH} = 14 \).
- If pH = 12, then:
\[
\text{pOH} = 14 - 12 = 2
\]

3. The concentration of hydroxide ions, \([OH^-]\), can be found using the formula:
\[
\text{pOH} = -\log[OH^-]
\]
- If \(\text{pOH} = 2\), then:
\[
[OH^-] = 10^{-2} \text{ M} = 0.01 \text{ M}
\]

4. Sodium hydroxide (NaOH) is known to be a strong base, meaning it dissociates completely in water to produce hydroxide ions.

Now, let's evaluate the provided statements:

- **The negative log of the concentration of OH ions is 12. Sodium hydroxide is a strong acid.** (Incorrect)
- **The negative log of the concentration of OH ions is 2. Sodium hydroxide is a strong acid.** (Incorrect)
- **The negative log of the concentration of OH ions is 12. Sodium hydroxide is a strong base.** (Incorrect)
- **The negative log of the concentration of OH ions is 2. Sodium hydroxide is a strong base.** (Correct)

The correct statement is: **The negative log of the concentration of OH ions is 2. Sodium hydroxide is a strong base.**