How do you standardize sodium thiosulphate solution?
Preparation and Standardization of 0.1 M Sodium Thiosulphate
- Take about 100 ml of water in a cleaned and dried 1000 ml volumetric flask.
- Add about 25 gm of Sodium Thiosulphate with continues stirring.
- Add about 0.2 gm of Sodium Carbonate with continues stirring.
- Add more about 700 ml of water, mix.
How do you standardize sodium thiosulfate using potassium iodate?
Take 10 ml of Potassium Iodate solution . Add 2 gm of Potassium Iodide and 5 ml of dilute H2SO4 ,keep it in dark for 10 minutes, add 2 to 3 drops of starch indicator and titrate with sodium thiosulphate using starch solution as indicator until the blue colour is disappeared.
What are the other ways to standardize na2s2o3?
From the above experiment it was evident that sodium thiosulpahte can be effectively standardized by using potassium dichromate and iodide with hydrochloric acid and starch as the visual indicator.
How many moles of na2s2o3 react with each mole of KIO3 used in the standardization?
Therefore, 6molofNa2S2O3 6 m o l o f N a 2 S 2 O 3 will react with each mole of KIO3.
Why do we standardize sodium thiosulphate solution?
Uniformity of reactions between iodine and sodium thiosulphate forms basis for utilizing the standard solution of iodine in the analysis of sodium thiosulphate. Sodium thiosulphate is usedin the analysis of iodine. In the analysis of iodine starch solution is used as indicator.
What is the equivalent weight of kio3?
| Potassium Iodate | |
|---|---|
| Chemical Formula | KIO3 |
| Formula Weight | 214.00 |
| Equivalent Weight (in moderately acidic solution) | 35.67 (Molar = 6 Normal)* |
| Equivalent Weight (in strongly acidic solution) | 53.50 (Molar = 4 Normal) |
Which primary standard is used in standardization of sodium thiosulphate?
The principle of standardization of sodium thiosulphate is based on redox iodometric titration with potassium iodate (primary standard). Potassium iodate is a strong oxidizing agent, it is treated with excess potassium iodide in acidic media which liberates iodine which is back titrated with sodium thioslphate.
Which indicator is used in Iodometry?
In an iodometric titration, a starch solution is used as an indicator since it can absorb the I 2 that is released. This absorption will cause the solution to change its colour from deep blue to light yellow when titrated with standardised thiosulfate solution.
What is the indicator in iodimetry?
starch
The indicator that is usually chosen for titrations involving iodine (triiodide) is starch. Starch forms a dark blue complex with iodine. The end point in iodimetry corresponds to a sudden color change to blue.
Can potassium iodate be titrated with sodium thiosulfate?
In the standardization, iodine (triiodide) liberated by potassium iodate in an acidic potassium iodide solution is titrated with a sodium thiosulfate … Investigation of iodine liberation process in redox titration of potassium iodate with sodium thiosulfate
How to prepare sodium thiosulphate solution?
PROCEDURE 1 Preparation of sodium thiosulphate solution. Dissolve 25 g of sodium thiosulphate in CO2 free water and make the volume upto 1000 ml. 2 Preparation of starch solution. 3 Standardization of sodium thiosulphate. 4 Tabulation of standardization.
Is sodium thiosulphate solution standardized against potassium dichromate?
Sodium thiosulphate solution is standardized against potassium dichromate in presence of hydrochloric acid and potassium iodide.
Why is thiosulphate not a primary standard?
The substance is therefore unsuitable as a primary standard. Among the variables affecting the stability of thiosulphate solutions are the pH, the presence of micro-organisms and impurities, the concentration of the solution and the presence of atmospheric oxygen.