Experiment midterm lab Flashcards
Experiment no. 9 Title:
To Prepare and Standardize 0.1 N Perchloric Acid
Experiment no. 10 Title:
To Prepare and Standardize 0.1 N Silver Nitrate
Experiment no. 11 Title:
Assay of Phenytoin
Experiment no. 12 Title:
To Prepare and Standardize 0.1 N Ammonium Thiocyanate
Experiment no. 13 Title:
Assay of Sodium Lauryl Sulfate for Sodium Chloride Content
Experiment no. 14 Title:
To Prepare and Standardize 01 N Sodium Methoxide
Materials Required in Experiment no. 9
8.5 ml of perchloric acid, 70.0 to 72.0%
1000 ml of glacial acetic acid
21 ml of acetic anhydride
700 mg of potassium biphthalate
Crystal violet TS
Materials Required in Experiment no. 10
17.5 g of silver nitrate
Diluted hydrochloric acid
Materials Required in Experiment no. 11
500 mg of phenytoin
50 ml dimethylformamide
Azo violet in benzene
Materials Required in Experiment no. 12
8.0g of reagent ammonium thiocyanate
silver nitrate
ml of ferric ammonium sulfate TS
Materials Required in Experiment no. 13
5 g of sodium lauryl sulfate
Dilute nitric acid (1 in 20)
2 mL of potassium chromate TS
0.1 N silver nitrate.
Materials Required in Experiment no. 14
2.5 g of sodium
150 ml of methanol
900 ml of benzene
400 mg of benzoic acid
Thymol blue in dimethylformamide (1 in 100)
80 ml of dimethylformamide
Experiment no. 9 Objectives:
- To successfully prepare and standardize 0.1 N perchloric acid
- To perform non aqueous titrimetric analysis
Experiment no. 10 Objectives:
- To successfully prepare and standardize 0.1 N silver nitrate
- To perform precipitation and complexation methods of analysis
Experiment no. 11 Objectives:
- To successfully assay phenytoin
- To perform non aqueous titrimetric analysis involving phenytoin
Experiment no. 12 Objectives:
- To successfully prepare and standardize 0.1 N Ammonium Thicyanate
- To perform precipitation and complexation methods of analysis involving ammonium
thiocyanate
Experiment no. 13 Objectives:
- To successfully assay Sodium Lauryl Sulfate for Sodium Chloride Content
- To perform precipitation and complexation methods of analysis involving sodium lauryl sulfate
Experiment no. 14 Objectives:
- To successfully prepare and standardize 01 N Sodium Methoxide
- To perform non aqueous titrimetric analysis involving sodium methoxide
Experiment no. 9 Procedure:
1.) Mix 8.5 ml of perchloric acid with 500 ml of glacial acetic acid and 21 ml of acetic anhydride, cool, and add glacial acetic acid to make 1000 ml.
2.) Standardize the solution as follows: Weigh accurately about 700 mg of potassium biphthalate, previously crushed lightly and dried at 120°C for 2 h, and dissolve it in 50 ml of glacial acetic acid in a 250-ml flask.
3.) Add 2 drops of crystal violet TS, and titrate with the perchloric acid solution until the violet color changes to emerald green.
4.) Deduct the volume of the perchloric acid consumed by 50 mL of the glacial acetic acid, and calculate the normality. Each 20.42 mg of potassium biphthalate is equivalent to 1 mL of 0.1 N perchloric acid.
Experiment no. 10 Procedure:
1.) Dissolve about 17.5 g of silver nitrate in 1000 ml of water, and standardize the solutions as follows: Pipet, or otherwise measure accurately, about 40 ml of the silver nitrate solution, and dilute with about 100 ml of water.
2.) Heat the solution, and add slowly with continuous stirring, diluted hydrochloric acid until precipitation of the silver chloride is complete.
3.) Boil the mixture cautiously for about 5 min, then allow it to stand in the dark until the precipitate has settled and the supernatant liquid has become clear.
4.) Transfer the precipitate to a tared filtering crucible, and wash it with small portions Of water slightly acidified with nitric acid. Dry the precipitate at 110°C to constant weight. From the weight of silver chloride, calculate the normality of the silver nitrate solution. Protect the silver chloride from light as much as possible during the determination.
Experiment no. 11 Procedure:
1.) Weigh accurately about 500mg of Phenytoin, and transfer to 125-ml conical flask.
2.) Dissolve in 50 ml of dimethylformamide, add 3 drops of saturated solution of azo violet in. benzene, and titrate with 0.1 N sodium methoxide to a blue end point. Each milliliter of 0.1 N sodium methoxide is equivalent to 25.23 mg of CH12N2O2
Experiment no. 12 Procedure:
Dissolve about 8 g of ammonium thiocyanate in 1000 ml of water. Place 30.0 ml of 0.1 N
silver nitrate in a 250-ml Erlenmeyer flask. Dilute with 50 ml of water, then add 2 ml of nitric acid
and 2 ml of ferric ammonium sulfate TS, and titrate with the ammonium thiocyanate solution to
the first appearance of a red brown color. Calculate the normality.
Experiment no. 13 Procedure:
Dissolve about 5 g, accurately weighed, in about 50 ml of water. Neutralize the solution with dilute nitric acid (1 in 20) using litmus paper as the indicator. Add 2 mL of potassium chromate TS, and titrate with 0.1 silver nitrate. Each milliliter of 0.1 N silver nitrate is equivalent to 5.844 mg of NaCl.
Experiment no. 14 Procedure:
1.) Cool in ice-water 150 ml of methanol contained in a 1000-ml volumetric flask, and add in small portions, about 2.5 g of freshly cut sodium metal..
2.) When the metal has dissolved, add sufficient benzene to make 1000 ml and mix. Store preferably in the reservoir of an automatic delivery buret suitably protected from carbon dioxide and moisture.
3.) Standardize the solution as follows: Weigh accurately about 400 mg of primary standard benzoic acid in 80 ml of dimethylformamide in a flask. Add 3 drops of a 1 in 100 salution of thymol blue in dimethylformamide, and titrate with sodium methoxide to a blue end point.
4.) Correct for the volume of the sodium methoxide solution consumed by 80 ml of the dimethylformamide, and calculate the normality. Each 12.21 mg of benzoic acid is
equivalent to 1 ml of 0.1 N sodium methoxide.
