Preparation of 1M hydrochloric acid (HCL)
Take 85 ml. of hydrochloric acid with water to produce 1000 ml. Standardize the solution in the following manner.
Standrazition 1M hydrochloric acid (HCL)
Weigh accurately about 1.5 gm. of anhydrous sodium carbonate, previously dried at about 270°C for 1 hour.
Dissolve it in 100 ml. of water and add 0.1 ml. of methyl red solution. Add the acid slowly from a burette, with constant stirring, until the solution becomes faintly pink. Heat the solution to boiling, cool and continue the titration.
Heat again to boiling and titrate further as necessary until the faint pink colour is no longer affected by continued boiling.
Every 1 ml of 1M hydrochloric acid is equivalent to 0.05299gm of Na2CO3
Calculation
Molarity = ---------------------------------
Volume consumed (ml) x 52.99 × 100
Preparation of 0.5M hydrochloric acid (HCL)
Take 42.5 ml of hydrochloric acid with water to produce 1000 ml. Standardize the solution as follows.
Standrazition o.5M hydrochloric acid (HCL)
Weigh accurately 0.750 gm. of anhydrous sodium carbonate, previously dried at about 270°C for 1 hour.
Dissolve it in 100 ml. of water and add 0.1 ml. of methyl red solution. Add the acid slowly from a burette, with constant stirring, until the solution becomes faintly pink. Heat the solution to boiling, cool and continue the titration.
Heat again to boiling and titrate further as necessary until the faint pink colour is no longer affected by continued boiling.
Each 1 ml of 0.5M hydrochloric acid is equivalent to 0.026495gm of Na2CO3
Calculation
Molarity = ------------------------------------
Volume consumed (ml) x 26.495 × 100
Preparation of 0.1M hydrochloric acid (HCL)
Take 8.5 ml of hydrochloric acid with water to produce 1000 ml. Standardize the solution as follows.
Standrazition 0.1M hydrochloric acid (HCL)
Weigh accurately 0.150 gm of anhydrous sodium carbonate previously dried at about 270°C for 1 hour.
Dissolve it in 100 ml. of water and add 0.1 ml. of methyl red solution. Add the acid slowly from a burette, with constant stirring, until the solution becomes faintly pink. Heat the solution to boiling, cool, and continue the titration.
Heat again to boiling and titrate further as necessary until the faint pink colour is no longer affected by continued boiling.
Each 1 ml of 0.1M hydrochloric acid is equivalent to 0.005299gm of Na2CO3
Calculation
Molarity = -----------------------------------------
Volume consumed (ml) x 5.299 × 100
Preparation of 0.02M hydrochloric acid (HCL)
Dilute 1.7 ml of hydrochloric acid with water to produce 1000 ml. Standardize the solution as follows.
Standrazition 0.02M hydrochloric acid (HCL)
Weigh approximately 0.030 gm. of anhydrous sodium carbonate previously heated at about 270°C for 1 hour.
Dissolve it in 100 ml. of water and add 0.1 ml. of methyl red solution. Add the acid slowly from a burette, with constant stirring, until the solution becomes faintly pink. Heat the solution to boiling, cool and continue the titration.
Heat again to boiling and titrate further as necessary until the faint pink colour is no longer affected by continued boiling.
Every 1 ml of 0.02M hydrochloric acid is equivalent to 0.0010598gm of Na2CO3
Calculation
Molarity = --------------------------------
Volume consumed (ml) x 1.0598 × 100
ACCEPTANCE CRITERIA
1) The accuracy of the solution should be within ± 10% of the theoretical concentration.
2) RSD* of the triplicate results of standardization/re-standardization should not be more than 0.2%.