Theoretic water yield

The theoretic water yield of catalyst in (5.107), WH2O, can be obtained from actual oxygen loss on the TG curves under reduction conditions, or calculated by... 

Place I g. of benzamide and 15 ml. of 10% aqueous sodium hydroxide solution in a 100 ml. conical flask fitted with a reflux water-condenser, and boil the mixture gently for 30 minutes, during which period ammonia is freely evolved. Now cool the solution in ice-water, and add concentrated hydrochloric acid until the mixture is strongly acid. Benzoic acid immediately separates. Allow the mixture to stand in the ice-water for a few minutes, and then filter off the benzoic add at the pump, wash with cold water, and drain. Recrystallise from hot water. The benzoic acid is obtained as colourless crystals, m.p. 121°, almost insoluble in cold water yield, o 8 g. (almost theoretical). Confirm the identity of the benzoic acid by the tests given on p. 347. 

The sulphanilic acid is dissolved in the sodium carbonate (i mol.) solution and the sodium nitrite (i mol.) solution added. The mixture is cooled in ice, and the solution of hydrochloi ic acid (i mol.) gradually added. The solution of dimethylaniline (i mol.) is now poured in, and the liquid made alkaline with caustic soda. The separation of methyl orange at once begins, and is assisted by the addition of a little common salt (20 grams). The precipitate is filtered at the pump, and crystallised from hot water. Yield, nearly theoretical. 

The filtrates are combined, cooled, and extracted with three successive 200 cc portions of ether. The pH of the filtrate is then raised to 3.5 with sodium hydroxide and the filtrate extracted with six successive 200 cc portions of ether to yield the balance of the product. The crude para-aminobenzoic acid product is recovered by evaporation of ether and is suspended in hot benzene, cooled and filtered to remove benzoic and toluic acids together with small amounts of impurities soluble in the filtrate. Recrystallization of the product from 200 cc of water yields 14.5 grams of light tan needles of para-aminobenzoic acid having an acid number of 411 (theoretical value 409). 

The collected ethereal filtrates were acidified with 50 ml of 4 N hydrochloric acid and tills solution was stirred vigorously. The hydrochloride of 1-(4 -benzyloxyphenyl)-2-(1 -methyl-2-phenoxy-ethylamino)propanone-1 precipitated out, was filtered off, washed with water and then with diethyl ether. Then this substance was dried in vacuo. The yield was 37.7 g, i.e., 89% of the theoretically possible yield, calculated on 1-(4 -benzyloxyphenyl)-2-bromine propanone-1. This substance had a light yellow color and melted at 197° to 198°C, while decomposing. 

Then 21.89 g of the hydrochloride salt was dissolved in 600 ml of 80% aqueous ethanol. With the addition of a palladium carbon catalyst, this solution was hydrogenated at room temperature under a hydrogen pressure of about 1.1 atmospheres. After 2 mols hydrogen had been absorbed, the catalyst was filtered off and the filtrate was evaporated in vacuo until crystallization occurred. Then the crystals were dissolved by heating in the smallest possible quantity of water and after cooling, the crystallized substance was filtered off, washed with water and dried in vacuo. The yield was 6.80 g, i.e., 39% of the theoretically possible yield. The resultant product recrystallized from water melted at 203° to 204°C. 

Yield.—80% theoretical (4-5 gms.). Colourless needles becomes yellow at 125°, then dark red, and melts at a higher temperature with alcohol or water yields hippuric acid. (B., 38, 605.)... 

Yields.—Iodosobenzene.—75% theoretical (6 gms.). White amorphous substance soluble in water, yielding a neutral solution decomposes when heated to above 240°. 

The Ti and Hf compounds are monomers, whereas the Zr complex was dimeric. As found by Hrncir and Skiles, the series of M[OSi(OBu-t)3]4 compounds are all moisture-sensitive. TGA studies indicate that the Ti complex decomposes cleanly at temperatures >240 °C and gives a ceramic yield of 25 wt% whereas the theoretical ceramic yield for TiSiC>4 should be 29.07 wt%. The primary gaseous thermolysis products were identified by mass spectroscopy to be isobutene and water. A likely pathway for decomposition appears to involve /1-hydrogen elimination followed by condensation of the resulting Si—OH groups to generate isobutene, water and an oxide network as shown in equations 66 and 67. 

Further enhancement of luminescence properties is possible through halogenation of the C-H group. With this improvement, the maximum theoretical quantum yield achievable (without water molecules and secondary ligand) is 14%, corresponding to a Yb(2Fs/2) lifetime of 140 ps (Tsvirko et al., 2001). 

Benzylethylpropylchlorosilicane is produced from benzylethyl-silicon diehloride (1 mol.) and propyl magnesium bromide (1 mol.). It is a colourless, fuming, mobile liquid, which generally becomes pink, and is immediately decomposed by water, yielding the corresponding silicol and oxide. It boils at 172° to 176° C. at 50 mm., and the yield is 50 to 60 per cent, of the theoretical. 

Taking into account that fructose loses three molecules of water during dehydration towards HMF, from 1 kg of fructose calculating the theoretical maximum yield only 0.7 kg of HMF could be obtained. When considering a favorable average molar yield of 70% for the dehydration, from 1 kg of fructose only 490 g of HMF could be obtained. 

When the electrolysis is finished, calculate the number of coulombs passed and the theoretical maximum yield of perchlorate in moles. Measure out an equal number of moles of potassium choride, in the form of a saturated (4M) solution, and stir this into the warm electrolyte. A fine perchlorate precipitate appears. Cool in ice and filter the potassium perchlorate on a small Buchner funnel. Wash with a little ice-cold water and suck as dry as possible then dissolve the crude product (which contains some chlorate) in 150 ml of hot water and recrystallize, cooling to below 10° before filtering off the crystals. Wash the crystals wdth about 50 ml of ice-cold 50 per cent alcohol, suck dry, and dry in air. The yield of recrystallized salt, based on the current consumption, is about 60 per cent. 

In the above manner, prepared from the chloride and ammonium thiocyanate and is used without recrystalhzation. It is heated to 130 (not above 134°). The theoretical loss in weight is 18.40 per cent. The product is quickly reciy-stallized from warm water. Yield 0.45 to 0.55 g. (60-65 per cent) for each.gram of starting material. Anal. Calcd. for [Cr(en)2(SCN)2](SCN) H20 Cr, 14.3. Found Cr, 14.4. 

---