| 1 M Sulphuric acid |
| 1.0 Scope: This procedure is applicable for the preparation and standardization of 1M sulphuric acid 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 2.5 10 ml volumetric pipette 3.0 Reagents: 3.1 H2SO4 AR grade 3.2 Anhydrous sodium carbonate AR grade 3.3 Methyl red solution 3.4 Ethanol (95 %v/v) 3.5 0.1M sodium hydroxide solution. 4.0 Preparation of Reagents: 4.1 Methyl red solution: Dissolve 50 mg of methyl red in a mixture of 1.86 ml of 0.1M sodium hydroxide and 50 ml of ethanol (95 %v/v). After solution is effected, add sufficient water to produce 100 ml and store in a well fitted transparent glass bottle. 5.0 Preparation: Add slowly, with stirring, 60 ml of sulphuric acid to about 1000 ml of water, allow it to cool 25°C. To read this SOP click here SOP for Entry And Exit Of Staff And Visitors. 6.0 Standardization Weigh accurately and transfer about 3 g of anhydrous sodium carbonate, previously heated at about 270°C for 1 hour to 250 ml glass stoppered conical flask. Dissolve it in 100 ml of water and add 0.1 ml of methyl red solution. By the Add sulphuric acid slowly slowly from a burette or pipette, with constant stirring, until the solution becomes faintly pink. Heating the solution to boiling, cool and continue the titration with the solution of 1M sulphuric acid. Heating again to boiling and titrate further as necessary until the faint pink colour is no longer affected by continued boiling in qc. Each ml of 1M sulphuric acid is equivalent to 0.10598 g of Na2CO3. 7.0 Calculation: Wt. of caco3 X 1.0 M= ———————– V X 0.10598 Where: M = molarity of 1M H2SO4 solution W = weight of sodium carbonate in gm. V = consumed volume of 1M H2SO4 solution in ml 8.0 Storage: Store in a well fitted transparent glass bottle. |