Answer :
To determine the pH of a 0.027 M KOH solution, we need to understand a few key concepts about pH and strong bases.
Step-by-Step Explanation:
Understanding KOH as a Strong Base:
- Potassium hydroxide (KOH) is a strong base. This means it dissociates completely in water into K⁺ ions and OH⁻ ions.
- Therefore, the concentration of OH⁻ ions in the solution is equal to the concentration of KOH, which is 0.027 M.
Calculating the pOH:
- The pOH is calculated using the formula:
[tex]\text{pOH} = -\log[\text{OH}^-][/tex] - Plug in the concentration of OH⁻ ions:
[tex]\text{pOH} = -\log(0.027)[/tex] - Calculate:
[tex]\text{pOH} \approx 1.57[/tex]
- The pOH is calculated using the formula:
Converting pOH to pH:
- The relationship between pH and pOH is given by the equation:
[tex]\text{pH} + \text{pOH} = 14[/tex] - From the calculated pOH:
[tex]\text{pH} = 14 - 1.57[/tex]
[tex]\text{pH} \approx 12.43[/tex]
- The relationship between pH and pOH is given by the equation:
Based on this calculation, the pH of a 0.027 M KOH solution is approximately 12.43.
Conclusion:
- The correct answer is (c) 12.43.
- This makes sense because KOH is a strong base, and we expect the pH to be greater than 7, which indicates a basic solution.