Grey Mixture

Phosphorus dissolves in arsenic trichloride on warming without reaction and is deposited on cooling.8 If the mixture is heated in the presence of aluminium chloride at 130° to 150° C. for 40 minutes, a brownish-red compound of composition A1As3C13 results,9 from which, however, aluminium chloride can readily be removed by water or ammonia, leaving a residue of finely divided black arsenic. If the compound is heated to 190° C. in the absence of air, it turns black as arsenic trichloride and aluminium chloride distil off and a bright grey mixture of arsenic and arsenide remains. It has been suggested that the arsenic is co-ordinatively bound, and that the compound may be /Ass... 

Place the reaction flask in a ultrasonic bath and switch the generator on. The initial grey mixture turns rapidly to a deep black, heavy suspension. 

The following substances form the groundwork of most firework compositions —Gun-powder ain powder and meal powder), saltpetre and sulphur charcoal mixture, and grey mixture. 

This mixture is the basis for most compositions which are to give light and also for grey mixture. 

Fining glue, 119 Fire balls, preparation of, 147 Fire, mixtures for producing coloured, 14S IlreworU compositions — charcoal mixture, 147 cold and warm mixtures, 151 grey mixture, 147 n powder, 146 ignition mixtures, lu illumination and coloured fire mixtures, 14 ... 

Add about 0 2 g. of ferrous sulphate crystals to the first portion of the filtrate contained in a boiling-tube. An immediate dark greenish-grey precipitate of ferrous hydroxide should occur if the mixture remains clear, add a few ml. of sodium hydroxide solution. Now boil the mixture gently for a few minutes to ensure formation of the ferrocyanide, cool under the tap, add one drop of ferric chloride solution, and then acidify... 

Dissolve 0-5 g. of the substance in 10 ml. of 50 per cent, alcohol, add 0-5 g. of solid ammonium chloride and about 0 -5 g. of zinc powder. Heat the mixture to boiling, and allow the ensuing chemical reaction to proceed for 5 minutes. Filter from the excess of zinc powder, and teat the filtrate with Tollen s reagent Section 111,70, (i). An immediate black or grey precipitate or a silver mirror indicates the presence of a hydroxyl-amine formed by reduction of the nitro compound. Alternatively, the filtrate may be warmed with Fehling s solution, when cuprous oxide will be precipitated if a hydroxylamine is present. Make certain that the original compound does not aflfect the reagent used. 

The palladium - barium sulphate catalyst Is prepared by treating a suspension of20g. of barium sulphate (which has been precipitated in hot solution) in 400 ml. of hot water with a solution of I - 7 g. of palladium chloride (equivalent to I - 0 g. of palladium) in 50 ml. of water and with I - 5 ml. of 40 per cent, formaldehyde solution. The mixture is rendered faintly alkaline to litmus by the addition of sodium hydroxide solution and then boiled for a short time. When the supernatant liquid is clear, the grey precipitate is filtered oS, and wa.shed with hot water until the... 

Lead, atomic number 82, is a member of Group 14 (IVA) of the Periodic Table. Ordinary lead is bluish grey and is a mixture of isotopes of mass number 204 (15%), 206 (23.6%), 207 (22.6%), and 208 (52.3%). The average atomic weight of lead from different origins may vary as much as 0.04 units. The stable isotopes are products of decay of three naturally radioactive elements (see Radioactivity, natural) comes from the uranium series (see Uraniumand... 

Barrett and his colleagues , and Kosakhave summarised existing information on the scales formed on nickel-chromium alloys. Up to about 10% Cr, the thick black scale is composed of a double layer, the outer layer being nickel oxide and the inner porous layer a mixture of nickel oxide with small amounts of the spinel NiO CrjOj. Internal oxidation causes the formation of a subscale consisting of chromium oxide particles embedded in the nickel-rich matrix. At 10-20% Cr the scale is thinner and grey coloured and consists of chromium oxide and spinel with the possible presence of some nickel oxide. At about 25-30% Cr a predominantly chromium oxide scale is... 

Pipette 25 mL barium ion solution (ca 0.01 M) into a 250 mL conical flask and dilute to about 100 mL with de-ionised water. Adjust the pH of the solution to 12 by the addition of 3-6 mL of 1M sodium hydroxide solution the pH must be checked with a pH meter as it must lie between 11.5 and 12.7. Add 50 mg of methyl thymol blue/potassium nitrate mixture [see Section 10.50(C)] and titrate with standard (0.01 M) EDTA solution until the colour changes from blue to grey. 

Fig. 6 IR spectra of adsorbed CO on 1 ML Co deposited at room temperature on the alumina fflm as a function of CO coverage. Spectra were taken at 44 K. Black trace second up from the bottom shows the spectrum resulting from saturation coverage of a 50 50 mixture of i CO i CO. Overlaid gray trace is artificially created by adding the saturation coverage spectra CO and CO scaled by a factor 1/2. Lowest black trace shows the spectrum of CO saturation coverage on particles grown hy 1 MLCo + 0.05 MLPd. Corresponding grey trace is the pure Co spectrum for comparison. Right inset shows TPD spectrum of 1 ML Co [64]...

Figure 2.7 Mass spectra recorded at different resolutions. Mass spectrum obtained by a two dimensional ion trap at low resolution (a) and by an Orbitrap at resolving power 50000 (b). Mass spectrum of a mixture of three isobaric species [C19H7N]+, [C20H9]+, [C13H19N302]+ obtained at low resolution (black line) and at resolving power 50000 (grey line) (c). It is noteworthy that at low resolution the three peaks are completely unresolved...

Fig. 17.10 Schafer et al.14 have observed single mode lasing from core shell CdSe/ZnS nano crystal quantum dots in a glycerine water mixture. The fluorescence spectrum (black line) showed clear peaks of WGM and single mode lasing (grey line) was observed for sufficiently small droplets ( 10 pm) and high pump laser intensities (53 mJ crrT2 in 10 ns pulses at 532 nm). Insert shows the droplet trapped between the electrodes. Reprinted from Ref. 14 with permission. 2008 American Chemical Society...

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