Nickel sulfate

Moissanite, see Silicon carbide Molybdenite, see Molybdenum disulfide Molybdite, see Molybdenum(VI) oxide Molysite, see Iron(III) chloride Montroydite, see Mercury(II) oxide Morenosite, see Nickel sulfate 7-water Mosaic gold, see Tin disulfide Muriatic acid, see Hydrogen chloride, aqueous solutions... 

Nickel sulfate NiS04 6H2O (pale blue) (green) ... 

Metals less noble than copper, such as iron, nickel, and lead, dissolve from the anode. The lead precipitates as lead sulfate in the slimes. Other impurities such as arsenic, antimony, and bismuth remain partiy as insoluble compounds in the slimes and partiy as soluble complexes in the electrolyte. Precious metals, such as gold and silver, remain as metals in the anode slimes. The bulk of the slimes consist of particles of copper falling from the anode, and insoluble sulfides, selenides, or teUurides. These slimes are processed further for the recovery of the various constituents. Metals less noble than copper do not deposit but accumulate in solution. This requires periodic purification of the electrolyte to remove nickel sulfate, arsenic, and other impurities. 

Nickel [7440-02-0] Ni, recognized as an element as early as 1754 (1), was not isolated until 1820 (2). It was mined from arsenic sulfide mineral deposits (3) and first used in an alloy called German Silver (4). Soon after, nickel was used as an anode in solutions of nickel sulfate [7786-81 A] NiSO, and nickel chloride [7718-54-9] NiCl, to electroplate jewelry. Nickel carbonyl [13463-39-3] Ni(C02)4, was discovered in 1890 (see Carbonyls). This material, distilled as a hquid, decomposes into carbon monoxide and pure nickel powder, a method used in nickel refining (5) (see Nickel and nickel alloys). 

Properties. Nickel sulfate hexahydrate [10101 -97-0], NiSo 6H20 is a monoclinic emerald-green crystalline salt that dissolves easily in water and in ethanol. When heated, it loses water and above 800°C decomposes into nickel oxide and SO3. Its density is 2.03 g/cm. ... 

Ma.nufa.cture. The preferred method for making nickel sulfate is adding nickel powder to hot dilute sulfuric acid. Adding sulfuric acid to nickel powder in hot water enhances the formation of H2S. Hydrogen sulfide always forms as a by-product upon reaction of metallic nickel and sulfuric acid. The hberated hydrogen is absorbed by the metal and then reduces the sulfate anion to H2S. 

Nickel sulfate also is made by the reaction of black nickel oxide and hot dilute sulfuric acid, or of dilute sulfuric acid and nickel carbonate. The reaction of nickel oxide and sulfuric acid has been studied and a reaction induction temperature of 49°C deterrnined (39). High purity nickel sulfate is made from the reaction of nickel carbonyl, sulfur dioxide, and oxygen in the gas phase at 100°C (40). Another method for the continuous manufacture of nickel sulfate is the gas-phase reaction of nickel carbonyl and nitric acid, recovering the soHd product in sulfuric acid, and continuously removing the soHd nickel sulfate from the acid mixture (41). In this last method, nickel carbonyl and sulfuric acid are fed into a closed-loop reactor. Nickel sulfate and carbon monoxide are produced the CO is thus recycled to form nickel carbonyl. 

Uses. Nickel nitrate is an intermediate in the manufacture of nickel catalysts, especially those that are sensitive to sulfur and therefore preclude the use of the less expensive nickel sulfate. Nickel nitrate also is an intermediate in loading active mass in nickel—alkaline batteries of the sintered plate type (see Batteries, SECONDARY cells). Typically, hot nickel nitrate symp is impregnated in the porous sintered nickel positive plates. Subsequendy, the plates are soaked in potassium hydroxide solution, whereupon nickel hydroxide [12054-48-7] precipitates within the pores of the plate. 

Ma.nufa.cture. Nickel carbonyl can be prepared by the direct combination of carbon monoxide and metallic nickel (77). The presence of sulfur, the surface area, and the surface activity of the nickel affect the formation of nickel carbonyl (78). The thermodynamics of formation and reaction are documented (79). Two commercial processes are used for large-scale production (80). An atmospheric method, whereby carbon monoxide is passed over nickel sulfide and freshly reduced nickel metal, is used in the United Kingdom to produce pure nickel carbonyl (81). The second method, used in Canada, involves high pressure CO in the formation of iron and nickel carbonyls the two are separated by distillation (81). Very high pressure CO is required for the formation of cobalt carbonyl and a method has been described where the mixed carbonyls are scmbbed with ammonia or an amine and the cobalt is extracted as the ammine carbonyl (82). A discontinued commercial process in the United States involved the reaction of carbon monoxide with nickel sulfate solution. 

Because of the delay in decomposition of the peroxide, oxygen evolution follows carbon dioxide sorption. A catalyst is required to obtain total decomposition of the peroxides 2 wt % nickel sulfate often is used. The temperature of the bed is the controlling variable 204°C is required to produce the best decomposition rates (18). The reaction mechanism for sodium peroxide is the same as for lithium peroxide, ie, both carbon dioxide and moisture are required to generate oxygen. Sodium peroxide has been used extensively in breathing apparatus. 

TABLE 2-63 Nickel Chloride (NiCI,) TABLE 2-64 Nickel Nitrate [Ni(N03),l TABLE 2-65 Nickel Sulfate (NiSO ) ... 

Ammonium nickel sulfate (6H2O) [7785-20-8 (6H20) 15699-18-0 (anhydr)] M 395.0, d... 

Nickel sulfate (7H2O) [1010-98-1] M Crystd from warm water (0.25mL/g) by cooling. 

AlWONIUM NICKEL SULFATE see NICKEL AMMONIUM SULFATE ... 

In this reaction, the nickel ions of the nickel sulfate (NiSO ) are exchanged for the calcium ions of the calcium hydroxide [Ca(OH)2 ] molecule. Similarly, a resin with hydrogen ions available for exchange will exchange those ions for nickel ions from solution. The reaction can be written as follows ... 

The same sort of competition for electrons is involved in reaction (11), in which Zn(s) releases electrons and Cu+2 accepts them. This time the competition for electrons is such that equilibrium favors Zn+2 and Cu(s). By way of contrast, compare the reaction of metallic cobalt placed in a nickel sulfate solution. A reaction occurs,... 

From the statement in the text that nickel metal reacts with H+ to give H2(g) and the additional information that zinc metal reacts readily with nickel sulfate solution, decide where to add the half-reaction Ni-Ni+2 in our list. 

If a chemist wishes to know whether zinc can be oxidized if it is placed in contact with a solution of nickel sulfate, the values of E° help him decide. The half-cell potential for Zn-Zn+2 is +0.76 volt, which is greater than that for Ni-Ni+2 (which is +0.25 volt). The difference, +0.51 volt, is positive, indicating that zinc has a greater tendency to lose electrons than does nickel. Therefore, zinc can transfer electrons to Ni+2. The chemist predicts zinc will react with Ni+2, zinc being oxidized and nickel being reduced. 

For example, by comparing E° s, we predicted that zinc would dissolve in nickel sulfate. These E° s show that zinc metal will dissolve if zinc ion and nickel ion are both present at 1 M concentration ... 

C03-0112. Nickel sulfate hexahydrate is NiSOq 6 H2 O. (a) Compute its molar mass, (b) Compute the number of moles contained in 25.0 g of this compound, (c) Determine its percent composition, (d) Determine the mass of this compound that contains 1.00 mol of O. 

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