Preparation
• Dissolve about 6 g of potassium hydroxide in 5 ml of water.
• Add sufficient aldehyde-free ethanol (95 %) to produce 1000 ml.
• Add sufficient aldehyde-free ethanol (95 %) to produce 1000 ml.
• Allow the solution to stand in a tightly-stoppered bottle for 24 hours.
• Then quickly decant the clear supernatant liquid into a suitable, tightly-closed container.
• Standardize the solution in the following manner.
• Then quickly decant the clear supernatant liquid into a suitable, tightly-closed container.
• Standardize the solution in the following manner.
Standardization
• Pipette 20.0 ml of 0.1 M hydrochloric acid into a flask.
• Dilute with 50 ml of water and add 0.1 ml of phenolphthalein solution.
• Titrate with the ethanolic potassium hydroxide solution until a permanent pale pink color is produced.
• Dilute with 50 ml of water and add 0.1 ml of phenolphthalein solution.
• Titrate with the ethanolic potassium hydroxide solution until a permanent pale pink color is produced.
• 1 ml of 0.1 M hydrochloric acid is equivalent to 0.00561 g of KOH.
