Preparation of mercury sulfide Mercury sulfide is conveniently prepared by direct synthesis from mercury and sulfur. Two modifications of this compound are known, one black, which is formed first in this preparation and also by precipitation of mercuric with the ions of sulfide. The other a brilliant red mercury sulfide or vermilion, which is more stable and into which the black form tends to change. Mercury Sulfide: 20 g of mercury and 8 g of sulfur are placed in a large porcelain mortar and triturated with moistening by sodium sulfide solution. When the globules of metallic mercury seem to have…
Author: Ethan Frank
Preparation of Potassium Ethyl Sulfate Ethyl Sulfate: To 80 ml of ethyl alcohol 20 ml of concentrated sulfuric acid are slowly added and well mixed by shaking. A considerable amount of heat is developed in the process. The reaction flask is heated for 2-3 hours under reflux, yielding ethyl hydrogen sulfate and small amount of sulfuric acid, unchanged ethyl alcohol. The reaction mixture on cooling with well stirring is poured into 500 ml of cold water and neutralized by adding calcium carbonate. Addition of calcium carbonate converts the free sulfuric acid to calcium sulfate and the ethyl hydrogen sulfate into…
Preparation of mercury ii fulminate/mercury fulminate mercury ii fulminate: 5 g of metallic mercury is added to 35 ml of concentrated nitric acid (d=1.42 g/ml) in a 100-ml Erlenmeyer flask, and the mixture is allowed to stand without shaking until the mercury has gone into solution. The acid liquid is then poured into 50 ml of 90% alcohol in a 500-ml beaker in the hood. The temperature of the mixture rises, a vigorous reaction commences, white fumes come off, and crystals of mercury ii fulminate soon begin to precipitate. ` Red fumes appear and the precipitation of the fulminate becomes more…
Your Guide to Freeing Up Storage on Digital Devices Computers, tablets, and smartphones have a limited amount of available disk storage. Some users do not encounter problems with running out of free space because they do not bother keeping that much stuff on their devices. On the other hand, there are plenty of people who would love to have more total storage available because the default setup seems to never be enough. If the problem sounds familiar and you want to find solutions to it, this article should be quite useful. Let’s take a look at some of the most…
Preparation of Sulfur Dichloride Sulfur Dichloride: Fifty grams of sulfur monochloride are placed in the distilling flask. About 0.1 g of iron powder is added to the liquid as a halogen carrier and dry chlorine is led in steadily (3-4 bubbles/sec) for one-half hour. The dark liquid that is produced is allowed to stand one hour and then one millilitre of phosphorus trichloride is added. The product is fractionated through a small column packed with glass and the portion that boils at 55-62°C is collected. This fraction is redistilled as before from a few drops of phosphorus trichloride and the pure…
Preparation of lead ii chloride Lead ii Chloride: 15 g of neutral lead acetate 3-hydrate are dissolved in 100ml of water and the solution made faintly acid to litmus with glacial acetic acid added dropwise. Filter if necessary and mix with a solution of 3.5g of sodium chloride in 25ml of water. The precipitation must be performed in the cold due to the solubility of the precipitated lead chloride in hot water. When the product has settled well, suction filter and wash the material thoroughly with alcohol (three 20-ml portions to facilitate drying) after draining off the mother liquor completely. Drying…
Synthesis of enone Enone: When Fetizon’s reagent is used, L-rhamnal is dissolved in benzene and then the Fetizon’s reagent is added to the mixture (20 g reagent: 1 g L-rhamnal). The mixture is refluxed for 1 hour, the spent reagent removed by filtration, and the solvent removed by evaporation to yield nearly pure enone. When the oxidant is chromium trioxide:pyridine complex, L-rhamnal is added to a solution of the oxidant in dichloromethane followed by addition of 4 equivalents of acetic anhydride. After 20 minutes the reaction mixture is poured onto a column of silica gel (ethyl acetate eluent) containing excess…
Synthesis of sodium hypobromite A cold solution of sodium hypobromite is prepared from 1.6 g. of sodium hydroxide, 3.2 g of bromine, and 10 g of ice and water. To this solution is added with stirring 1-[7-chloro-4,10-dihydro-1-methyl-10-oxo-1H[1]benzoxepino[4,3-b]pyrrole-2-yl]propan-2-one (Q) (1.5 g, 0.005 m), while keeping the temperature below 10° C. The resulting mixture is stirred at low temperature for an additional 4 hours before water and ether are added. The layers are separated and the aqueous layer is treated with a sufficient amount of sodium bisulfite. The treated aqueous layer is filtered and the filtrate acidified with 2 N hydrochloric acid…
Synthesis of Si OCH3 4 1642 gm of crude product prepared in Example 3 was added to the distilling flask and heated slowly. Distillation fractions were collected at the head temperatures shown in Table 4 . From the composition of the fractions, the 1642 gm of crude product afforded 660 gm trimethoxysilane, which is more than that calculable from the composition of the starting material (first row of Table 4). The additional tri-methoxy silane was formed via the disproportionation of the mixed dimethylaminomethoxysilanes,. The vapor phase methanolysis consumed 2521 gm tris(dimethylamino)silane and 1005 gm methanol and produced a total of…
Preparation of Lead Chloride / Lead ii Chloride Lead Chloride / Lead ii Chloride: 15 g of neutral lead acetate 3-hydrate are dissolved in 100ml of water and the solution made faintly acid to litmus with glacial acetic acid added dropwise. Filter if necessary and mix with a solution of 3.5g of sodium chloride in 25ml of water. The precipitation must be performed in the cold due to the solubility of the precipitated lead chloride in hot water. When the product has settled well, suction filter and wash the material thoroughly with alcohol (three 20-ml portions to facilitate drying) after draining…