Wednesday, December 29, 2021

Preparation and standardization of 0.1 M potassium hydroxide

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

Aim:

To prepare and standardize 0.1 M potassium hydroxide solution using HCl.

Requirements:

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

Chemicals: Potassium hydroxide (KOH), hydrochloric acid (HCl), and phenolphthalein indicator, etc.

Preparation of 0.1 M potassium hydroxide solution:

Take properly weighed 06.00 gm of potassium hydroxide and add in 500 ml of distilled water, Once it has completely dissolved, make up the volume to 1000 ml with water.

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.
  • Titrate 20.0 ml of the solution with 0.1 M hydrochloric acid using 0.5 ml of phenolphthalein solution as an indicator,
  • The actual endpoint is indicated by the appearance of a violet color to blue.
  • 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 potassium hydroxide solution.
  • 1 ml of 0.1 M HCl is equivalent to 0.005611 g of KOH.

Observation table:

Sr. No.

Content in conical flask

 

Burette reading

Volume of titrant used (ml)

Initial

Final

1

 

 

 

 

2

 

 

 

3

 

 

 

 

Mean:


Result:

The strength of the prepared potassium hydroxide solution was found to be_____M.


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