Monday, December 27, 2021

Preparation and standardization of 0.1 M sodium nitrite

Learn about the preparation and standardization of 0.1 M sodium nitrite solution through a laboratory experiment or practical.

Aim:

To prepare and standardize 0.1 M sodium nitrite solution using sulfanilamide.

Requirements:

Glasswares: Burette, burette stand, conical flask, volumetric pipette, beaker, volumetric flask, funnel, glass rod, and wash bottle, etc.

Chemicals: Sulfanilamide (C6H8N2O2S), hydrochloric acid (HCl), potassium bromide (KBr), and sodium nitrite (NaNO2), etc.

Preparation of 0.1 M sodium nitrite solution:

Take properly weighed 07.50 gm of sodium nitrite and dissolve in 800 ml of distilled water, once it has completely dissolved, make up the volume to 1000 ml.

Titration procedure:

  • All glassware should be cleaned and dried according to standard laboratory procedures.
  • Before filling the burette for the titration, rinse it with distilled water and then pre-rinse it with a portion of the titrant solution. Pre-rinsing is required to make sure that all solution in the burette is the desired solution, not a contaminated or diluted solution.
  • Take the unknown stock solution of titrant in a clean and dry beaker then fill the burette using the funnel.
  • Remove air bubbles from the burette and adjust the reading to zero.
  • In a 50.00 ml 2M hydrochloric acid solution, dissolve 0.3 gm of sulphanilamide.
  • Add 03.00 g KBr, cool on ice, and titrate with prepared 0.1 M sodium nitrite solution until the endpoint, which is determined potentiometrically.
  • To get accurate results, repeat the titration three times.
  • Properly record the readings of the burette.
  • Take their mean and calculate the molarity of the sodium methoxide solution.

Observation table:


Sr. No.

Content in conical flask

 

Burette reading

Volume of titrant used (ml)

Initial

Final

1

 

 

 

 

2

 

 

 

3

 

 

 

 

Mean:


Calculations:


1 ml of 0.1 M sodium nitrite is equivalent to 0.01722 g of sulphanilamide.

M = Sulphanilamide in mg / NaNO2 in ml x 17.22

Result:

The strength of the prepared sodium nitrite solution was found to be_____M.


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