Iodine flask

A 1-ml. or 2-ml. aliquot of the benzene solution of peroxybenzoic acid is pipetted into an iodine flask, the walls of the flask are rinsed with a small quantity of chloroform, and 15 ml. of... 

Procedure Weigh accurately 0.5 g arsenic trioxide into a beaker, add to it 2 ml of sodium hydroxide solution, and heat to dissolve. Cool and transfer the contents quantitatively to a 100 ml volumetric flask and make up the volume upto the mark with DW. Pipette 20 ml into an iodine-flask, acidify with dilute HC1 carefully and confirm it by adding a little NaHC03 to remove the free excess acid, followed by a further 2 g to get rid of HI formed in the reaction mixture. Now, titrate with 0.1 N iodine solution till the end-point is achieved by the appearance of the first permanent pale straw colour. 

Procedure Weigh accurately about 0.1 g of benzylpenicillin in DW and dilute to 100 ml in a volumetric flask. Transfer 10.0 ml to an iodine flask, add 5 ml of N sodium hydroxide and allow to stand for 20 minutes. Now, add 20 ml of freshly prepared buffer solution, 5 ml of N HC1 and 25.0 ml of 0.02 N iodine solution. Close the flask with a wet glass-stopper and allow to stand for 20 minutes in a dark place (i.e., protected from light). Titrate the excess of iodine with 0.02 N sodium thiosulphate, employing freshly prepared starch solution as an indicator added towards the end-point. 

Procedure Pipette 25 ml of a standard 0.1 N AgN03 solution into a glass-stoppered flask (iodine-flask), dilute with 50 ml of DW, add to it 2 ml of nitric acid and 2 ml of ferric ammonium sulphate solution and titrate with ammonium solution to the first appearance of red-brown colour. Each ml of 0.1 N silver nitrate is equivalent to 0.007612 g of NH4SCN. 

Procedure Transfer 25 ml of 0.1 N bromine solution with the help of a pipette into a 500 ml iodine flask and dilute it with 120 ml of DW. Add to it 5 ml of hydrochloric acid, moisten the glass-stopper with water and insert the stopper in the flask. Shake the contents gently. Now, add 5 ml of potassium iodide solution, again lace the stopper and allow the resulting mixture to stand for 5 minutes in the dark. Titrate the liberated iodine with previously standardized 0.1 N sodium thiosulphate solution, adding 3 ml of freshly prepared starch solution towards the end-point. Each ml of 0.1N sodium thiosulphate is equivalent to 0.01598 g... 

Procedure Weigh accurately about 0.2 g of ethacrynic acid, dissolve in 40 ml of glacial acetic acid in a 250 ml iodine flask. Add to it 20 ml of 0.1 N bromine and 30.0 ml of hydrochloric acid, immediately place in position the moistened stopper to the ffask, mix the contents vigorously and allow it to stand in a dark place for 60 minutes (to complete the reaction with bromine). Add to it 100 ml of water and 20 ml of KI Solution and titrate immediately with 0.1 sodium thiosulphate, employing freshly prepared starch solution as an indicator towards the end of the titration. Repeat an operation without the pharmaceutical substance (blank titration) thus the difference between the titrations represents the amount of bromine required by the ethacrynic acid. Each ml of 0.1 N bromine is equivalent to 0.01516 g of C13H12C1204. 

Procedure Weigh accurately 0.15 g of mephenesin and dissolve in 50 ml of DW into a 250 ml iodine-flask. Add to it 25.0 ml of 0.1 N potassium bromate solution and 10.0 g of powdered potassium bromide. After the dissolution of KBr, add 10 ml of hydrochloric acid, insert the moistened stopper, and after 10 seconds add 10 ml of potassium iodide solution. Titrate with 0.1 N sodium thiosulphate using starch solution as indicator. Each ml of 0.1 N potassium bromate is equivalent to 0.00911 g of C10H,4O3. 

The purity of the hypochlorite may be determined by iodo-metric titration. This titration is run conveniently by weighing out a small portion of the hypochlorite (<0.5 g.) in a 4-ml. vial and then dropping the vial and its contents into an iodine flask containing 20 ml. of glacial acetic acid, 10 ml. of water, and 3 g. of potassium iodide. The titration is then conducted in the usual fashion. 

Accurately weigh the amount recommended below of the polymer to be analyzed into the 250-ml iodine flask. Record the weight of the polymer. 

Accurately weigh 2-3 g of polymer into the iodine flask. 

Active oxygen content is determined iodometrically 3 In an iodine flask, an accurately weighed sample (0.1-0.3 g.) is dissolved in 20 ml. of an acetic acid-chloroform solution (3 2 by volume), and 2 ml. of saturated aqueous potassium iodide solution is added. The flask is immediately flushed with nitrogen, stoppered, and allowed to stand at room temperature for 15 minutes. Fifty milliliters of water is then added with good mixing, and the liberated iodine is titrated with 0.1 A sodium thiosulfate, employing starch as indicator. A blank titration, which usually does not exceed 0.2 ml., is also run. One milliliter of 0.1 N sodium thiosulfate is equivalent to 0.00821 g. of tetralin hydroperoxide. 

To the 50ml soln in the iodine flask, add 25ml of 0.2N standard potassium bromate-bromide soln (prepd as described in Method 605-1 of MIL-STD-286A), accurately measured to within 0.01ml... 

Moisten the stopper of the iodine flask with a drop of 15% KI soln and add 5ml of 38% HCI. Observe the time and stopper tbe flask immediately swirl it for a few seconds and after 1 min of bromination, counting from the time of addg HCI, add 10ml of 15% KI soln and swirl the flask. If an oil. separates, add 25ml of carbon tetrachloride... 

B = Na thiosulfate requited to titrate the liberated iodine in the iodine flask, ml... 

Bromination Method. Transfer an accurately weighed 0.9—l.Og sample to a 250ml iodine flask provided with a glass stopper and dissolve it. in 25ml of chloroform. Add 60ml of glac AcOH, followed by exactly 10.0ml of... 

Mineral Jelly (Ref l),Evaporate most of the ether from the extract on a water bath. Remove the remainder with a stream of air. Dry the residue in an oven at 60° C for 1 hour. Then add 20 ml of 80% methyl alcohol (by volume) and heat to gentle boiling on a water bath. Decant the hot solvent thru a small funnel fitted with a 7 cm No 41 Whatman filter paper and collect the filtrate in an iodine flask. Retain as much mineral jelly in the extraction flask as possible. Repeat the extraction twice, using 10 ml of 80% methyl alcohol making 40 ml in all. Finally wash the filter paper six times with hot 80% methyl alcohol... 

Wt of proplnt x (100-% VM) EthylCentralite (Carbamite) (Ref 1). Distill the methyl alcohol from the iodine flask (above) on a water bath. Take care that all methyl alcohol is removed, but do not overheat the Carbamite,... 

In 100-mL aliquot of the above filtrate dissolve 5 g of NaCl with stirring. Add HC1 solution dropwise to adjust the pH to approximately 7 or slightly less. A pH meter should be used to measure the pH. Transfer the sample to a 250-mL iodine flask or a wide mouth conical flask. 

Arsenic may be determined iodometricaQy. A dried sample of 150-200 mg. is mixed with 7 ml. of 15 N nitric acid and the solution boiled gently for 5-10 minutes. Three milliliters of 2 AT sodium bromate is then added and the mixture evaporated gently to dryness. The residue is taken up in 150 ml. of 4 M hydrochloric acid in an iodine flask then 1 g. of sodium hydrogen carbonate is cautiously mixed in to displace the air, followed by 1 g. of potassium iodide. The flask is then stoppered and allowed to stand 5 minutes. The contents are rapidly titrated with 0.05 N sodium thiosulfate to the disappearance of the iodine color. 

Washing. Weighed samples of textile were immersed in 25-50 mL of distilled water or reagent grade CC14 in a stoppered iodine flask at ambient temperature without agitation. After 24 hr, the samples were removed from the wash liquid and dried to constant weight in a constant temperature humidity room (23°C 50% r.h.). Dyed samples washed in... 

Assay Prepare an acetylating reagent, within one week of use, by mixing 3.4 mL of water and 130 mL of acetic anhydride with 1000 mL of anhydrous pyridine. For the Assay, pipet 20 mL of this reagent into a 250-mL iodine flask, and add about 1 g of sample, accurately weighed. Attach a dry reflux condenser to the flask, and reflux for 1 h. Allow the flask to cool to room temperature, then rinse the condenser with 50 mL of chilled (10°) carbon dioxide-free water, allowing the water to drain into the flask. Stopper the flask, cool to below 20°, add... 

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