| 0.1M Sodium hydroxide |
| 1.0 Scope: This procedure is applicable for preparation and standardization of 0.1M sodium hydroxide 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 Reagent solution preparation: 3.1 NaOH AR grade 3.2 Potassium hydrogen phthalate AR grade 3.3 Phenolphthalein solution 3.4 Ethanol (95%v/v) 4.0 Preparation of Reagents: Phenolphthalein solution: Dissolve 1.0 gram of phenolphthalein in ethanol (95%v/v) and diluted 100.0 ml and store in a well fitted transparent glass bottle in wet lab. To read this GTP click here Preparation of 1 M Sulphuric acid. 5.0 Preparation: Dissolve about 4.2 gm of sodium hydroxide in sufficient milli-Q water to produce 1000 ml. Transfer the solution in a cleaned and dried plastic bottle. Keep the solution at least for an hour. 6.0 Standardization: Weigh accurately and transfer about 0.5 g of potassium hydrogen phthalate, previously powdered and dried about 120oC for 2 hours to a 250 ml glass stoppered conical flask and dissolve in 75 ml of water. Add 0.1 ml of phenolphthalein solution and titrate with the 0.1 M sodium hydroxide solution until a permanent pink colour is produced. 7.0 Calculation: W X 1000 N=————————– V X 204.23 Where: N = molarity of 0.1M sodium hydroxide W = Wight of potassium hydrogen phthalate(C8H5KO4) in gm V = consumed volume of 0.1M sodium hydroxide in ml 8.0 Storage: Preserve the solution in clean glass-screw bottle at room temperature. |