To analyze the problem, let's break down the information provided:
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pH of the solution: The pH of the solution A is 12.
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Relation between pH and pOH: The pH and pOH of a solution are related by the equation: \[ \text{pH} + \text{pOH} = 14 \] From this, we can find the pOH: \[ \text{pOH} = 14 - \text{pH} = 14 - 12 = 2 \]
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Concentration of OH- ions: The concentration of hydroxide ions \([\text{OH}^-]\) can be calculated using the relationship: \[ \text{pOH} = -\log[\text{OH}^-] \] Therefore, \[ 2 = -\log[\text{OH}^-] \] Which means: \[ \log[\text{OH}^-] = -2 \] Thus, \[ [\text{OH}^-] = 10^{-2} = 0.01 , \text{M} \]
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Conclusion about sodium hydroxide: Sodium hydroxide (NaOH) is known to be a strong base that completely dissociates in water to give \(\text{Na}^+\) and \(\text{OH}^-\). Hence, if the solution has a pH of 12, it confirms that sodium hydroxide is indeed a strong base.
Now, reviewing the available options based on the above calculations:
- The negative log of the concentration of OH- ions is 2 (which corresponds to pOH).
- Sodium hydroxide is a strong base.
Thus, the correct response would be: "The negative log of the concentration of OH- ions is 2. The sodium hydroxide is a strong base."
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