What is the pH of a solution prepared by mixing 100.00 mL of 0.020 M Ca(OH)₂ with 50.00 mL of 0.200 M NaOH? Assume that the volumes are additive. A)12.90 B)12.97 C)13.15 D)13.45

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Quizplus · Accepted Answer

First, calculate the moles of OH- from each solution. For Ca(OH)2, which dissociates into Ca2+ and 2 OH-, the moles of OH- are 0.020 M * 0.100 L * 2 = 0.004 moles. For NaOH, the moles of OH- are 0.200 M * 0.050 L = 0.010 moles. The total moles of OH- are 0.004 + 0.010 = 0.014 moles. The total volume of the solution is 100.00 mL + 50.00 mL = 150.00 mL or 0.150 L. The concentration of OH- in the final solution is 0.014 moles / 0.150 L = 0.0933 M. The pOH is -log(0.0933) = 1.03, and since pH + pOH = 14, the pH is 14 - 1.03 = 12.97.

What Is the PH of a Solution Prepared by Mixing