| Preparation and standardization of 0.1M potassium hydroxide ethanolic |
| 1.0 Scope: This procedure is applicable for preparation and standardization of 0.1M KOH ethanolic solution. 2.0 Apparatus: 2.1 1000 ml volumetric flask 2.2 250 ml glass-stoppered conical flask 2.3 100 ml graduated burette 2.4 100 ml volumetric flask 3.0 Reagents solution preparation: 3.1 Potassium hydroxide AR grade 3.2 0.1M hydrochloric acid solution 3.3 Phenolphthalein solution 3.4 Ethanol (95%v/v) To read this SOP click here Preparation and Standardization of 0.1M Potassium hydroxide. 4.0 Preparation of Reagents: Phenolphthalein solution: Dissolve about 1 g of phenolphthalein in ethanol (95%v/v) and dilute 100 ml and store in a well fitted transparent glass bottle. 5.0 Preparation: Dissolve about 6.0 g of potassium hydroxide(KOH) in 5.0 ml of purified water/water for injection and add sufficient aldehyde free ethanol (95%v/v) to produce 1000 ml. Allow the soln to stand in a tightly-stoppered bottle for 24 hours. Then quickly decant the clear supernatant liquid into a suitable, tightly-closed container in quality control department. 6.0 Standardization: Titrate 20.0 ml of the soln with 0.1M hydrochloric acid(HCl) into a flask, dilute with 50.0 ml of purified water/water for injections, add 0.1 ml of phenolphthalein in soln and titrate with the ethanolic potassium hydroxide(KOH) soln until a permanent pale-pink colour is produced. Each ml of 0.1 M HCl is equivalent to 0.005611 g of KOH. 7.0 Calculation: N2* V2. = N3* V3. N2 = N3* V3 / V2Where: N2. = molarity of potassium hydroxide ethanolic solution V2 = volume cons. of KOH ethanolic solution in ml N3 = molarity of 0.1M HCL solution V3. = 20 millilitre of 0.1 M HCL solution 8.0 Storage: Store in a well fitted transparent glass bottle. |
