Answer:
Calcium hydroxide (Ca(OH)2) is a strong base that dissociates completely in water to form calcium ions (Ca2+) and hydroxide ions (OH-).
The balanced chemical equation for the reaction of Ca(OH)2 in water is:
Ca(OH)2 → Ca2+ + 2 OH-
In this case, the initial concentration of Ca(OH)2 is 0.0675 M.
Since each mole of Ca(OH)2 produces two moles of OH-, the concentration of OH- in the solution can be calculated as follows:
[OH-] = 2 x 0.0675 M = 0.135 M
Now, we can use the following equation to find the pOH of the solution:
pOH = -log[OH-] = -log(0.135) = 0.869
Therefore, the pOH of the 0.0675 M Ca(OH)2 solution is 0.869.
To determine if the solution is acidic or basic, we can use the fact that pH + pOH = 14 for any aqueous solution at room temperature. In this case, the pH can be calculated as follows:
pH = 14 - pOH = 14 - 0.869 = 13.131
Since the pH is greater than 7, the solution is basic.