Learn about the preparation and standardization of 0.1 M lead nitrate solution through a laboratory experiment or practical.
Aim:
To prepare and standardize 0.1 M lead nitrate solution using standard 0.1M EDTA (volumetric solution).
Requirements:
Glasswares: Burette, burette stand, conical flask, volumetric pipette, beaker, volumetric flask, funnel, glass rod, and wash bottle, etc.
Chemicals: Lead nitrate (Pb(NO3)2) disodium edetate (EDTA), hexamine (C6H12N4), and Xylenol Orange mixture, etc.
Preparation of 0.1M lead nitrate solution:
Take properly weighed 33.12 gm of lead nitrate 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.
- Take 50.00 ml of a prepared solution of lead nitrate and pour it into a conical flask.
- Then, as an indication, add 50 mg of xylenol orange mixture and enough hexamine to make a violet-pink color.
- Titrate it with 0.1 M disodium edetate solution with constant stirring until the endpoint.
- The actual endpoint is indicated by the appearance of a lemon yellow color.
- 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 lead nitrate 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 disodium edetate is equivalent to 0.03312 g of lead (II) nitrate.
M = Molarity of EDTA x reading of the burette / 33
Result:
The strength of the prepared lead nitrate solution was found to be_____M.
Frequently Asked Questions (FAQ):
What is the molecular mass of lead (II) nitrate?
Lead (II) nitrate is an inorganic compound with the chemical formula Pb(NO3)2 and its molecular weight is 331.2 g/mol.
Which primary standard is used in the standardization of 0.1 normal AgNO3?
Sodium chloride is used as the primary standard in the standardization of 0.1 normal AgNO3.
You may also like this
No comments:
Post a Comment