A saturated aqueous solution of calcium hydroxide has a pH of 12.25. What is the [Ca2+] of such a solution?

2 answers

In the absence of other information (temperature) write molecular formula for calcium hydroxide and complete the word equation below as a chemical equation.

calcium hydroxide = calcium ions + hydroxide ions

This will tell you how many moles of hydroxide ions are associated with one mole of calcium ions.

Use [H+]=10^-pH to calculate the [H+]

The use 10^-14=[H+][OH-] to calculate [OH-]

Then knowing how many moles of hydroxide ions are associated with one mole of calcium ions you can calclate [Ca2+]
8.8914 * 10^-3 moles per litre of solution