Zinc sulphate, 2.23

Vernon claims that in outdoor atmospheres the corrosion product consists largely of zinc oxide, hydroxide and combined water, but also contains zinc sulphide, zinc sulphate and carbonate. The following table gives the composition of typical films formed in an industrial atmosphere. 

Sulphur and its compounds in the air can become oxidised to sulphuric acid this forms soluble zinc sulphate, which is washed away by rain ... 

When a metal is immersed in a solution containing its own ions, say, zinc in zinc sulphate solution, a potential difference is established between the metal and the solution. The potential difference E for an electrode reaction... 

An interesting application of electrode potentials is to the calculation of the e.m.f. of a voltaic cell. One of the simplest of galvanic cells is the Daniell cell. It consists of a rod of zinc dipping into zinc sulphate solution and a strip of copper in copper sulphate solution the two solutions are generally separated by placing one inside a porous pot and the other in the surrounding vessel. The cell may be represented as ... 

Zinc-ion solution. Dissolve about 7.0 g of analytical grade zinc sulphate heptahydrate in 25 mL of Reagent I. 

Solutions of EDTA of the following concentrations are suitable for most experimental work 0.1M, 0.05M, and 0.01 M. These contain respectively 37.224 g, 18.612g, and 3.7224 g of the dihydrate per litre of solution. As already indicated, the dry analytical grade salt cannot be regarded as a primary standard and the solution must be standardised this can be done by titration of nearly neutralised zinc chloride or zinc sulphate solution prepared from a known weight of zinc pellets, or by titration with a solution made from specially dried lead nitrate. 

Pipette 25 mL of an aluminium ion solution (approximately 0.01 M) into a conical flask and from a burette add a slight excess of 0.01 M EDTA solution adjust the pH to between 7 and 8 by the addition of ammonia solution (test drops on phenol red paper or use a pH meter). Boil the solution for a few minutes to ensure complete complexation of the aluminium cool to room temperature and adjust the pH to 7-8. Add 50 mg of solochrome black/potassium nitrate mixture [see Section 10.50(C)] and titrate rapidly with standard 0.01 M zinc sulphate solution until the colour changes from blue to wine red. 

Every millilitre difference between the volume of 0.01 M EDTA added and the 0.01 M zinc sulphate solution used in the back-titration corresponds to 0.2698 mg of aluminium. 

The standard zinc sulphate solution required is best prepared by dissolving about 1.63 g (accurately weighed) of granulated zinc in dilute sulphuric acid, nearly neutralising with sodium hydroxide solution, and then making up to 250 mL in a graduated flask alternatively, the requisite quantity of zinc sulphate may be used. In either case, de-ionised water must be used. 

Procedure. Weigh out accurately about 10 g of the salt and dissolve it in 250 mL of water in a graduated flask. Pipette 25 mL of this solution into a 250 mL conical flask, add about 20 mL of 10 per cent potassium iodide solution, 2 mL of 1M sulphuric acid, and 15 mL of a solution containing 2.0 g crystallised zinc sulphate. Titrate the liberated iodine immediately with standard 0.1M sodium thiosulphate and starch add the starch solution (2 mL) after the colour has faded to a pale yellow. The titration is complete when the blue colour has just... 

If a bar of zinc is dipped into a solution of zinc sulphate, the former acquires a negative, the latter a positive charge, and a difference of potential is established at the boundary the magnitude of which depends on the concentration of the solution. There is in fact an electrical double layer produced, which is formed of negative charges on the metal (which has lost ions into the solution) ... 

Mercury and silver have long been known to have antibacterial properties and preparations of these metals were among the earliest used antiseptics, but have been replaced by less toxic compounds. Other metals such as zinc, copper, aluminium and tin have weak antibacterial properties but are used in medicine for other functions, e.g. aluminium acetate and zinc sulphate are employed as astringents. 

The equivalent procedure for the main olfactory epithelial sheet (MOEx) is chemical ablation by treatment with (5%) zinc sulphate solution. The adoption of this approach was determined by practical anatomy, given the inevitably partial, let alone traumatic, results of cutting/scraping epithelia from the intricately folded sensory surfaces (Negus, 1958). 

Zinc chalcogenide thin hlms have been grown by ECALE using zinc sulphate as metal source and sodium sulphide and sodium selenite as chalcogenide precursors.145-148 The formation of the hrst layers of ZnS on (lll)Au has been analyzed by STM and XPS.145 HRSEM images showed that the him surface was very hat, even at an atomic level. On the other hand, thicker ZnS hlms were formed of well-separated crystal nuclei. The stoichiometry of a thicker ZnS him showed a slight excess of sulphur, with a Zn S ratio of 1 1.2. The band gap of a thicker him (deposition time 12 h) was 3.60eV.147... 

Benvenuti, S. and A. Gagliardo. 1996. Homing behaviour of pigeons subjected to unilateral zinc sulphate treatment of their olfactory mucosa. Jour. Exp. Biol. 199 2531-2535. 

Shukla, J.P. and K. Pandey. 1986b. Effect of a sublethal concentration of zinc sulphate on the growth rate of fingerlings of Channa punctata (Bloch), a freshwater murrel. Acta Hydrochim. Hydrobiol. 14 677-680. 

Solbe, J.F.D.L.G. and V.A. Flook. 1975. Studies on the toxicity of zinc sulphate and of cadmium sulphate to stone loach Noemacheilus barbatulus (L.) in hard water. Jour. Fish Biol. 7 631-637. 

Blood should be deproteinized by some technique which leaves no extra salt, acid, or alkali in the supernatant Some suitable techniques are with tungstic acid, with ethanol (BIO), or with zinc sulphate and barium hydroxide (S21). The supernatant is desalted in the same way as urine and, if necessary, concentrated before applying to the paper. Subsequent technique is as for urine. 

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