 We're going to determine the KSP of calcium hydroxide by titration technique. We're going to pipette 25 milliliters of a saturated solution of calcium hydroxide into the flask. We're going to add a few drops of bromethymol blue indicator. Bromethymol blue is an acid-based indicator that is blue in basic solution and yellow in acidic solution. We're going to titrate the saturated solution of calcium hydroxide with a standardized solution of HCl. We've taken an initial burette reading. We'll slowly add the HCl until the solution turns a pale yellow color. We'll rinse down the flask, make the walls the flask to make sure everything gets a chance to react. Now we've reached a pale yellow endpoint. We'll take a final burette reading. We're now going to look at the molar solubility of calcium hydroxide in a solution containing calcium chloride as an example of the common ion effect. We're going to pipette 25 milliliters of a solution of saturated solution of calcium hydroxide in a solution containing calcium chloride. We're going to add a couple of drops of bromethymol blue indicator. Bromethymol blue is an acid-based indicator is blue in basic solution and yellow in acidic solution. We're going to titrate the solution of calcium hydroxide and calcium chloride with a standardized solution of hydrochloric acid. We've taken an initial burette reading. We're going to slowly add the HCl solution until our indicator turns pale yellow. We're close to the endpoint. We're going to rinse down the walls of the flask. We've now reached the yellow endpoint and we'll take a final burette reading.