Phenolphthalein Solution

Phenolphthalein Solution

Dissolve 0.1 g of phenolphthalein R in 80 ml of alcohol R and dilute to 100 ml with water R .

Complies with the following test.

Test for sensitivity To 0.1 ml of the phenolphthalein solution add 100 ml of carbon dioxide-free water R . The solution is colourless. Not more than 0.2 ml of 0.02 m sodium hydroxide is required to change the colour to pink.

Colour change pH 8.2 (colourless) to pH 10.0 (red)