Potassium Acetate Solution Acid Sulphate

Sulphates. — Dilute 10 cc. of potassium acetate solution with 10 cc. of water, acidify with hydrochloric acid and add barium chloride solution. No change should appear. 

Alternative procedure. The following method utilises a trace of copper sulphate as a catalyst to increase the speed of the reaction in consequence, a weaker acid (acetic acid) may be employed and the extent of atmospheric oxidation of hydriodic acid reduced. Place 25.0 mL of 0.017M potassium dichromate in a 250 mL conical flask, add 5.0 mL of glacial acetic acid, 5 mL of 0.001M copper sulphate, and wash the sides of the flask with distilled water. Add 30 mL of 10 per cent potassium iodide solution, and titrate the iodine as liberated with the approximately 0.1M thiosulphate solution, introducing a little starch indicator towards the end. The titration may be completed in 3-4 minutes after the addition of the potassium iodide solution. Subtract 0.05 mL to allow for the iodine liberated by the copper sulphate catalyst. 

Tartaric Acid and Sulphates. — On adding potassium acetate and barium nitrate solutions to a solution of 1 gm. of succinic acid in 20 cc. of water, no precipitate should form on standing twelve hours. 

Carbon Disulphide.f — Thoroughly mix 50 cc. of benzene with 50 gin. of alcoholic potassium hydroxide solution (11 gm. of potassium hydroxide in 90 gm. of absolute alcohol), and allow the mixture to stand several hours at a temperature of about 20° C. Shake with about 100 cc. of water, remove the aqueous solution from the benzene, neutralize the latter with acetic acid, and add copper-sulphate solution. No precipitate should form. 

Sulphates, Copper, and Alkalies. — Boil for a few minutes a solution of 5 gm. of ferrous chloride in 10 cc. of water and 5 cc. of nitric acid (sp. gr. 1.3), dilute to 120 cc., add 20 cc. of ammonia water, and filter evaporate 50 cc. of the filtrate and ignite the residue. The weight of the latter should not exceed 0.001 gm. Slightly acidulate 20 cc. of the filtrate with hydrochloric acid and add barium nitrate solution. No change should appear. 20 cc. of the filtrate acidified with acetic acid should show no change upon addition of potassium ferrocyanide solution. 

Lead acetate solution white precipitate of lead sulphate, PbS04, soluble in hot concentrated sulphuric acid, in solutions of ammonium acetate and of ammonium tartrate (see under Lead, Section III.4, reaction 5), and in sodium hydroxide solution. In the last case sodium tetrahydroxoplumbate(II) is formed, and on acidification with hydrochloric acid, the lead crystallizes out as the chloride. If any of the aqueous solutions of the precipitate are acidified with acetic acid and potassium chromate solution added, yellow lead chromate is precipitated (see under Lead, Section III.4, reaction 6). 

Copper, Nitric Acid, etc. (Alkali Salts, Calcium). — Dilute 20 iM. of ferric chloride solution (1 1) with 100 cc. of water, fuld 25 cc. of ammonia water, and filter. On evaporating 50 cc. of the colorless filtrate and igniting the residue, the weight of the latter should not exceed 0.001 gm. On mixing 2 cc. of the filtrate with 2 cc. of concentrated sulphuric acid, and overlaying tliis mixture with 1 cc. of ferrous sulphate solution, no brown zone should form at the contact-surfaces of the two licpiids. 20 cc. of the filtrate acidulated With acetic a

potassium ferrocyanide solution. 

Involutin (145) is responsible for the intense brown stain produced when the fruit body of Paxillus involutus is bruised. It formed a penta-acetate which, on oxidation with chromium trioxide or potassium permanganate solution gave a mixture of 3,4-diacetoxybenzoic acid and 4-acetoxybenzoic acid. With dimethyl sulphate and sodium hydroxide the trimethyl ether (151) resulted 201, 202). These observations, coupled with spectroscopic comparison with model compounds, established the nature of the cyclopentanoid nucleus and the level of hydrox-... 

In connection with this subject of chameleon pictures, it may be useful to note (1) that a solution of sulphate of copper and chloride of ammonia (blue) turns green when heated. (2) Glide of cobalt dissolved in acetic acid and a little potassium nitrate added, under the action of heat, develops a pale rose. (3) The original colour of tourmeric paper is affected by ammonia and restored on the application of heat. 

Pipette 25.0 cm of 0.09 M zinc sulphate solution, dilute to 100 cm with water and dissolve in the solution 5 g purest potassium acetate and 4 g glacial acetic acid. Warm the solution to 60°C and add with stirring a 2% solution of oxine in 2 M acetic acid. Boil for a few minutes to coagulate the precipitate. Check for complete precipitation, adding a slight excess of the oxine solution. Filter in a prepared G4 sinter, wash with hot water and dry at 130° to constant weight. Calculate from duplicate determinations, the average [Zn(ll)] in mol dm. ... 

Decant the liquid layer into a 2 5 litre flask, and dissolve the sodium derivative of acetylacetone in 1600 ml. of ice water transfer the solution to the flask. Separate the impiue ethyl acetate layer as rapidly as possible extract the aqueous layer with two 200 ml. portions of ether and discard the ethereal extracts. Treat the aqueous layer with ice-cold dilute sulphimic acid (100 g. of concentrated sulphiu-ic acid and 270 g. of crushed ice) until it is just acid to htmus. Extract the diketone from the solution with four 200 ml. portions of ether. Leave the combined ether extracts standing over 40 g. of anhydrous sodium sulphate (or the equivalent quantity of anhydrous magnesium sulphate) for 24 hours in the ice chest. Decant the ether solution into a 1500 ml. round-bottomed flask, shake the desiccant with 100 ml. of sodium-dried ether and add the extract to the ether solution. Distil off the ether on a water bath. Transfer the residue from a Claisen flask with fractionating side arm (Figs. II, 24, 4r-5) collect the fraction boiling between 130° and 139°. Dry this over 5 g. of anhydrous potassium carbonate, remove the desiccant, and redistil from the same flask. Collect the pure acetji-acetone at 134r-136°. The yield is 85 g. 

Diphenyl sulphoxide was obtained when a solution of diphenyl sulphide was treated with potassium hydrogen sulphate in ethanol and acetic acid ... 

Materials Required Salbutamol sulphate 50 mg solution of an equimolar mixture of anhydrous sodium carbonate and potassium carbonate (3% w/v in DW) 5.0 ml Solution of curcumin (0.125% w/v in glacial acetic acid) 3.0 ml mixture of H2S04 and glacial CH3COOH (5 ml 5 ml) 3.0 ml ethanol (96%) 100 ml solution of boric acid (dissolve 5 g of boric acid in a mixture of 20 ml DW and 20 ml absolute ethanol and dilute to 250 ml with absolute ethanol) 100 ml. 

---