Zinc-Copper nitrate

In the previous section efficient catalysis of the Diels-Alder reaction by copper(II)nitrate was encountered. Likewise, other bivalent metal ions that share the same row in the periodic system show catalytic activity. The effects of cobalt(II)nitrate, nickel(II)nitrate, copper(II)nitrate and zinc(ll)nitrate... 

As a third oxidation-reduction example, suppose a strip of metallic zinc is placed in a solution of copper nitrate, Cu(N03)j. The strip becomes coated with reddish metallic copper and the bluish color of the solution disappears. The presence of zinc ion, Zn+2, among the products can be shown when the Cu+2 color is gone. Then if hydrogen sulfide gas is passed into the mixture, white zinc sulfide, ZnS, can be seen. The reaction between metallic zinc and the aqueous copper nitrate is... 

Alone, or Metals, or Metal compounds Mellor, 1940, Vol. 8, 327 1967, Vol. 8, Suppl. 2.2, 84, 96 It is an explosive of positive oxygen balance, less stable than ammonium nitrate, and has been studied in detail. Stable on slow heating to 300°C, it decomposes explosively on rapid heating or under confinement. Presence of zinc, copper, most other metals and their acetylides, nitrides, oxides or sulfides cause flaming decomposition above the m.p. (70°C). Commercial cobalt (cubes) causes an explosion also. 

Correlation plots for the North Pacific Ocean concentration data from Figure 11.14 (a) zinc versus nitrate, phosphate, and silica, (b) cadmium versus nitrate, phosphate, and silica, (c) copper versus nitrate, phosphate, and silica, and (d) nickel versus nitrate, phosphate, and silica. 

Catalysts suitable specifically for reduction of carbon-oxygen bonds are based on oxides of copper, zinc and chromium Adkins catalysts). The so-called copper chromite (which is not necessarily a stoichiometric compound) is prepared by thermal decomposition of ammonium chromate and copper nitrate [50]. Its activity and stability is improved if barium nitrate is added before the thermal decomposition [57]. Similarly prepared zinc chromite is suitable for reductions of unsaturated acids and esters to unsaturated alcohols [52]. These catalysts are used specifically for reduction of carbonyl- and carboxyl-containing compounds to alcohols. Aldehydes and ketones are reduced at 150-200° and 100-150 atm, whereas esters and acids require temperatures up to 300° and pressures up to 350 atm. Because such conditions require special equipment and because all reductions achievable with copper chromite catalysts can be accomplished by hydrides and complex hydrides the use of Adkins catalyst in the laboratory is very limited. 

A branched-chain iodo sugar derivative, l,5-anhydro-4,6-0-benzyl-idene-2,3-dideoxy-3-C-(iodomethyl)-D-rifoo-hex-l-enitol [4,6-O-ben-zylidene-3-deoxy-3-C-(iodomethyl)-D-allal] (200), is one of the products formed on treatment of methyl 4,6-0-benzylidene-2,3-dideoxy-a-D-en/thro-hex-2-enopyranoside (77) with the Simmons-Smith reagent (diiodomethane and zinc-copper couple).123,212 Compound 200 displays high solvolytic reactivity, an observation that has been rationalized by supposing the formation of the highly stabilized carbonium ion213 (201). Thus, under conditions wherein methyl 2,3,4-tri-0-acetyl-6-deoxy-6-iodo-a-D-glucopyranoside required more than 24 hours to react appreciably with an excess of silver nitrate in 50% aqueous p-dioxane buffered with silver carbonate, the iodide 200 was hydrolyzed completely in less than 1 minute the product of hydrolysis of 200 is the cyclopropyl aldehyde 202. Methanolysis of... 

Tin and lead are the most rapid precipitants of metallic silver from the nitrate cadmium, zinc, copper, bismuth, and antimony axe moro slow in their operation, and mercury still more tardy. Chloride of silver is rapidly reduced by most of the metals which form soluble chlorides, such as zinc, iron, cadmium, cobalt, and arsenic. Zinc, copper, and arsenic rapidly reduce the ammoniacal solution of oxide of silver. Of all the metallic precipitants, zinc and cadmium are the most effective but when zinc or antimony aro used, the separated silver contains these metals. 

DOC, nitrate, phosphate, silicate, iron, ammonium, algal pigments, 02, zinc, copper, aluminum, lead, DMS, LMW compounds, manganese Alkalinity... 

A powder which burns with a green flame is obtained by the addition of nitrate of baryta to chlorate of potash, nitrate of potash, acetate of copper. A white flame is made by the addition of sulfide of antimony, sulfide of arsenic, camphor. Red by the mixture of lampblack, coal, bone ash, mineral oxide of iron, nitrate of strontia, pumice stone, mica, oxide of cobalt. Blue with ivory, bismuth, alum, zinc, copper sulfate purified of its sea water [sic]. Yellow by amber, carbonate of soda, sulfate of soda, cinnabar. It is necessary in order to make the colors come out well to animate the combustion by adding chlorate of potash.15... 

Zinc and copper nitrates on silica gel are able to oxidize benzylic and saturated secondary alcohols but not aliphatic primary alcohols.157 On the other hand, ZrO(OAc)2 is able to catalyze, under the action of f-BuOOH, the oxidation of benzylic alcohols—both primary and secondary—and primary saturated alcohols to aldehydes and ketones, while secondary saturated alcohols are very unreactive.158... 

The teacher should show students samples of solutions of copper nitrate, Cu(N03)2, iron nitrate, Fe(N03)3, cobalt nitrate, Co(N03)2, nickel nitrate, Ni(N03)2 and zinc nitrate, Zn(N03)2. List the solution name and formula and color. Name the metal element in each compound. 

Uses Cadmium (Cd) (L. cadmia Gr. kadmeia, ancient name for calamine, zinc carbonate) was discovered by Stromeyer in 1817 through an impurity in zinc carbonate. Cadmium most often occurs in small quantities associated with zinc ores, such as sphalerite (ZnS). The important compounds used in industry are cadmium oxide (CdO), cadmium chloride (CdCl2), cadmium nitrate (CdfNCRh), cadmium sulfide (CdS), and cadmium sulfate (CdSC>4). Greenockite (CdS) is the only mineral of any consequence bearing cadmium. Cadmium is also obtained as a by-product in the treatment of zinc, copper, nonferrous metal industry, and lead ores. Cadmium is a highly toxic heavy metal that forms complex compounds with other metals and elements. 

Dilute nitric acid attacks copper, forming copper nitrate, a soluble salt, so that the surface of the metal remains free until the copper has all reacted. Copper oxide may be obtained by heating the solution, first to expel the water, and then with a somewhat stronger heat to decompose the residue of copper nitrate oxides of nitrogen escape as red fumes, and copper oxide remains as a black solid. This is the method by which zinc was converted quantitatively into zinc oxide, page 24. 

Plant use of iron depends on the plant s ability to respond chemically to iron stress. This response causes the roots to release H+ and deduct ants, to reduce Fe3+, and to accumulate citrate, making iron available to the plant. Reduction sites are principally in the young lateral roots. Azide, arsenate, zinc, copper, and chelating agents may interfere with use of iron. Chemical reactions induced by iron stress affect nitrate reductase activity, use of iron from Fe3+ phosphate and Fe3+ chelate, and tolerance of plants to heavy metals. The iron stress-response mechanism is adaptive and genetically controlled, making it possible to tailor plants to grow under conditions of iron stress. 

Lewis acids can also be exploited for the cleavage of isopropylidene derivatives. One of the mildest examples comes from a synthesis of Lankacidin in which cleavage of an isopropylidene acetal without harm to a p-methoxybenzyl ether was effected with copper(Il) chloride dihydrate in methanol at reflux [Scheme 3.11].13 Alternatively, zinc(II) nitrate hexahydrate in acetonitrile at 50 DC can be used in which case even a primary tert-butyldimethylsilyl ether survives [Scheme 3.12].14 During a synthesis of Quinocarin, Katoh and co-workerscleaved an isopropylidene group using iron(IIT) chloride adsorbed onto silica gel [Scheme 3.13]. 

Predict the simplest equation for the reaction in the case of a) sodium nitrate, (Jj) copper nitrate, (c) lead nitrate, d ) zinc nitrate, e) ammonium nitrate, when heated. Verify the equations. 

An alternate procedure involves the precipitation of mixed copper and chromium hydroxides from a solution of chromium nitrate and copper nitrate by the addition of an sodium bicarbonate and then heating the precipitate to 300°-500°C.30 In this procedure, the copperchromium ratio can be varied over a wide range. A ratio between four and eight was optimum for use in the hydrogenation of esters to alcohols (Eqn. 13.6).30 A related Zn-CrO catalyst prepared by the decomposition of precipitated zinc-copper hydroxides was effective in the hydrogenation of unsaturated esters to unsaturated alcohols (Eqn. 13.7). 0 The presence of a small amount of alumina increased catalyst activity and selectivity. Some of these catalysts, however, tend to become colloidal on use so they can present separation problems. O... 

The active material, i.e. catalyst, of CuO/ZnO (3 7 by mole ratio) mixed oxides was prepared from the aqueous solution (aq. soln.) of reagent grade copper nitrate and zinc nitrate by adding diluted ammonium water. The precipitate was washed and calcined at 360°C in air for 1 day. On the other hand, Cu/ZnO powder was prepared by mechanical mixing of Cu powder (Rare Metallic Co., Ltd. 4N, -325 me.sh) and ZnO (Nacalai Tesque Inc. >99.0%) with a mole ratio of 3 7. 

Metal Displacement. A metal in a compound can be displaced by another metal in the elemental state. We have already seen examples of zinc replacing copper ions and copper replacing silver ions (see p. 121). Reversing the roles of the metals would result in no reaction. Thus copper metal wiU not displace zinc ions from zinc sulfate, and silver metal will not displace copper ions from copper nitrate. 

Kohoszka, G. F., Reimann, C. W., Allen, H. C., Gordon, G. (1967) Optical and magnetic measurements on single crystals of copper-doped tris(l,10phenanthroline) zinc(II) nitrate trihydrate. Inorg. Chem. 6, 1657. 

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