Copper gauze

Beilstein s test A method for detecting the presence of halogen in an organic compound. A piece of copper gauze is heated in an oxidiz-... 

Acrylic acid [79-10-7] M 72.1, m 13°, b 30°/3mm, d 1.051, pK 4.25. Can be purified by steam distn, or vacuum distn through a column packed with copper gauze to inhibit polymerisation. (This treatment also removes inhibitors such as methylene blue that may be present.) Azeotropic distn of the water with benzene converts aqueous acrylic acid to the anhydrous material. 

Kupfer-bromid, n. copper bromide, specif, cupric bromide, copper(II) bromide, -bro-mtir, n. cuprous bromide, copper(I) bromide, -chlorid, n. copper chloride, specif, cupric chloride, copper(II) chloride, -chloriir, n. cuprous chloride, copper(I) chloride, -cyamd, Ti. copper cyanide, specif, cupric cyanide, copper(II) cyanide, -cyaniir, n. cuprous cyanide, copper(I) cyanide, -dom, m. slag from liquated copper, -draht, m. copper wire, -drahtnetz, n. copper gauze, -drehspane,... 

Into a size 6A porcelain boat (88 X 13 X 10 mm.) is placed 10.0 g. (0.0113 mol) of Ag2ReBr6 (as much as 15 g. may be processed readily), and the boat is positioned near the sealed end of a 25 X 300 mm. Pyrex tube fitted with an inner 29/44 S.T. sleeve joint. The tube is connected to a mechanical vacuum pump (capable of reducing the pressure to ca. 50 p) via either a trap cooled by liquid nitrogen or a trap cooled by a Dry Ice-isopropyl alcohol slush, which is in turn connected to an 11-mm. Vycor combustion tube packed with copper gauze and maintained at 600° by means of a furnace. (Either protective system between the tube and the pump will serve to remove bromine, one of the reaction products.)... 

The cathode is a rolled strip of copper gauze which fits snugly into a 3 X in. test tube and rests on a glass-wool plug which covers a hole of about -in. diameter blown in the bottom of the test tube. During the preparation, the solution about half fills the tube, and the glass-wool plug protects the bulk of the oxidized solution from the cathode. 

Since the acetaldehyde cannot be separated by fractional distillation from the ether in which it has been collected, it is converted into the crystalline aldehyde-ammonia. The contents of the two receivers are transferred to a small filter jar which is cooled in a freezing mixture, and ammonia gas is led in from a cylinder. The delivery tube for the current of ammonia is a straight calcium chloride tube with its wide end deeply submerged in the liquid. To break up the crystalline mass which is formed, this tube is frequently moved to and fro. The jar is kept covered with a clock-glass (bored), piece of cardboard, or copper gauze. On account of the ether which evaporates, all flames in the vicinity must be extinguished. 

Reduction of a Metal Oxide wear eye protection ). Assemble the apparatus shown in Fig. 44 and check its tightness. Put 40-50 pieces of granulated zinc into a 250-ml flask. Pour anhydrous calcium chloride into U-shaped tube. Put 0.3 g of copper oxide into the wide part of a refractory tube, and a piece of copper gauze or foil (why ) into the gas-discharge tube out of which hydrogen will flow. Pour 100-150 ml of a 20% sulphuric acid solution into the flask. Again check... 

Preparation of Metal Sulphides from the Elements. Perform the experiment in a fume cupboard ) Copper Sulphide. Fill one-third of a test tube with sulphur and heat it up to boiling. The sulphur vapour should fill the entire tube. Hold a piece of copper gauze or foil with pincers, heat it in the flame of a burner until red hot, and rapidly introduce it into the sulphur vapour. What happens Write the equation of the reaction. How does copper snlphide react with water and hydrochloric acid ... 

Weigh 1 g of magnesium (powder or freshly cut shavings) in porcelain boat 8 and insert it into quartz tube 9 placed in electric furnace 10. Cut out two or three strips of thin copper gauze and pre-... 

Put the reduced copper into the middle part of porcelain tube 5 in furnace 6. What role should the copper gauze play A titanium powder can be used instead of the copper gauze. Titanium heated up to 500-600 °C in a nitrogen atmosphere forms a nitride that absorbs oxygen very well, transforming into titanium dioxide at 400-500 °C. 

Miller. Calfee and Bigelow made 1,1,2,2-tetrachlorodifluorOethane from a vapor-phase reaction of fluorine/nitrogen mixtures with hexachloroethane or tetrachlorocthene over copper gauze. Calfee and Bigelow fluorinated ethane likewise, obtaining hexafluoroethane and carbon tetrafluoride. 

Hadley and Bigelow fluorinated methane with fluorine/nitrogen mixtures in the vapor phase over copper gauze. All four fluoromethanes were obtained, together with hexafluoroethane and octafluoropropane. As an explanation, the first specific free-radical chain mechanism to be published for a fluorination process was invoked. 

BEILSTEIN S TEST. A test to detect halogens m organic compounds. Copper gauze is heated in a flame until the flame shows no green color if the addition of an organic compound produces a green flame, a halogen is present. 

Each c.c. of free space corresponds with 20 sq. cms. of catalyst surface. E. I. Orloff observed the oxidation of ammonia when mixed with air and passed over a heated copper gauze 4NH3-f-302 =2N2+6H20, with traces of nitrous and nitric acids—aniline, toluidine, and pyridine were oxidized in a similar way. W. W. Scott and W. D. Leech found that the conversion efficiency of cobalt oxide at 600°-800° is 79 3 per cent. This is augmented when about 3 per cent, of bismuth, or 10 to 12 per cent, of alumina, is used as... 

In further experiments (Collins Eggleton, 1965), miniature irradiated U02 fuel elements were heated to 1500°C in either CC /CO or C02/air mixtures. Between 30 and 50% of I, Te and Cs fission products were released, but less than 0.2% of Sr. In C02/air the released iodine was mainly elemental (as determined by adsorption on copper gauzes in May Packs). In C02/CO, iodine was released as a mixture of alkyl iodides, with methyl iodide dominant. The mode of formation of alkyl iodides in these experiments remains uncertain. 

For this, mechanical sieves made of aluminium or copper gauze, 50 meshes per 1 cm2, are used. Figure 122 shows a system which may be used. A wooden funnel (1) serves for leading the product, Lumps of picric acid are retained by gauze (2) and... 

A — Anode (from graphite platos), B — Diaphragm, K — Copper gauze cathode, L — Brine inlet, — Brine outlet (for saturation with salt), S — Fixing of electrode, St — Supports for diaphragm and cathode, Z — Cement lining of the frame. 

As has been mentioned in 1, smooth surfaces of copper, including those deposited electrolytically, reduced copper mirrors, and polished surfaces were quite inactive (a, i) a minute trace of activity only was occasionally detected in commercial copper gauze, but copper prepared by thermal decomposition of either cupric or cuprous oxides, or copper salts of mono- and dibasic fatty acids, by condensation on china-clay rods2 from the vapour (in nitrogen, to prevent oxidation), or by stirring up the atoms of copper into open formation by heating in ammonia at 820°, was active (t). 

Wind a 1.5- x 5-cm strip of 20-mesh copper gauze around the end of a copper wire. Heat the gauze in a nonluminous flame of a Bunsen burner until it glows without coloring the... 

---