To analyze the situation, let’s start with the information provided:
- The pH of the solution is 12.
- To find the concentration of hydroxide ions (OH⁻), we can use the relationship between pH, pOH, and the concentration of OH⁻.
Steps:
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Calculate pOH: \[ \text{pOH} = 14 - \text{pH} = 14 - 12 = 2 \]
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Calculate the concentration of OH⁻ ion from pOH: \[ \text{pOH} = -\log[\text{OH}^-] \] \[ 2 = -\log[\text{OH}^-] \implies [\text{OH}^-] = 10^{-2} = 0.01 \text{ M} \]
Given these calculations:
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The conclusion is that the negative log of the concentration of OH⁻ ions is 2, indicating a significant concentration of OH⁻ ions, which is characteristic of a strong base.
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Since sodium hydroxide (NaOH) is known to be a strong base, it further supports this assertion.
Therefore, the correct statement and conclusion about sodium hydroxide is:
The negative log of the concentration of OH⁻ ions is 2. Sodium hydroxide is a strong base.