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Nitric acid deposition

Acid rain affects plants by changing the conditions in the soil. For example, nitric acid deposits nitrates, which fertilize the land. The nitrates allow fast-growing weeds such as quack grass to replace valuable prairie species. If these species were to become extinct, their genetic material would no longer be available for agricultural research. [Pg.551]

The solubility of SO2 in water is strongly dependent on its pH, becoming limited below pH = 4. The presence of other pollutants can be important as they affect the pH of the liquid layer on the surface, which may also be buffered by corrosion products per se. Nitric acid deposits quite readily, for example, and could lower the pH and thus inhibit SO2 uptake. On the other hand, many atmospheric particulates are basic, and the limited literature on dew chemistry (Cadle and Goblicki) (22) does not indicate acidic dew composition, (it should be noted that these data were all taken in low SO2 environments). [Pg.426]

The primary purpose of the acid rain NOx emission reduction program is to reduce the adverse effects of acidic deposition on natural resources, ecosystems, visibility, materials, and public health by substantially reducing annual emissions of NOx- NOx emissions are a principal acidic deposition precursor. Although sulfate deposition is considered to be the major contributor to long-term aquatic acidification, nitric acidic deposition plays a dominant role in the "acid pulses" associated with the fish kills observed during the springtime meltdown of the snowpack in sensitive watersheds. [Pg.15]

Amino-4 -methylthiazole slowly decomposes on storage to a red viscous mass. It can be stored as the nitrate, which is readily deposited as pink crystals when dilute nitric acid is added to a cold ethanolic solution of the thiazole. The nitrate can be recrystallised from ethanol, although a faint pink colour persists. Alternatively, water can be added dropwise to a boiling suspension of the nitrate in acetone until the solution is just clear charcoal is now added and the solution, when boiled for a short time, filtered and cooled, deposits the colourless crystalline nitrate, m.p. 192-194° (immersed at 185°). The thiazole can be regenerated by decomposing the nitrate with aqueous sodium hydroxide, and extracting the free base with ether as before. [Pg.306]

Insert the tube E to within 1 inch of the bottom of the Carius tube, open the tap slightly, and allow the acid (about 10 drops) to run in. Then withdraw the dropping-tube, taking great care that traces of nitric acid are not deposited on the upper sides of the tul. ... [Pg.503]

As of 1996 world production of sodium nitrate was about 520,000 metric tons annually. Of this quantity, some 450,000 t (86%) are produced in Chile from natural deposits by SQM Nitratos and distributed worldwide by several affOiates, eg, Chilean Nitrate Corporation in the United States and Nitrate Sales International in Belgium. The remainder, ca 70,000 t, is manufactured mainly in Europe, Japan, and Russia, generally as a by-product of nitric acid production. Additionally, China is known to manufacture some unknown but significant volumes of sodium nitrate for domestic use. [Pg.195]

Alkali metal nitrates can be prepared by direct reaction of aqueous nitric acid on the appropriate hydroxide or carbonate. LiN03 is used for scarlet flares and pyrotechnic displays. Large deposits of NaN03 (saltpetre) are found in Chile and were probably formed by bacterial decay of small marine organisms the NH3 initially produced... [Pg.89]

Investigation into the effect has been mainly devoted to reactions with red fuming nitric acid . It seems that in red fuming nitric acid a preliminary reaction results in the formation of a surface deposit of finely divided metallic titanium ignition or pyrophoricity can then be initiated by any slight impact or friction. The tendency to pyrophoricity increases as the nitrogen dioxide content of the nitric acid rises from zero to maximum solubility at about 20%, but decreases as the water content rises, the effect being nearly completely stifled at about 2% water. [Pg.879]

Attack on the substrate by contact with Mg(OH>2 and Ca(OH)2 (calcareous scale) can also cause deplatinisation to occur. Anodes located close to the cathode or operating at high current densities can lead to a rapid build up of calcareous deposit, the major constituents of which are Mg(OH)2 and Ca(OH>2. The alkaline conditions so generated can lead to rapid dissolution of the platinum. The calcareous deposit can be removed by washing with dilute nitric acid. [Pg.168]

Resistance to corrosion Most authors who compare resistance to corrosion of electroless nickel with that of electrodeposited nickel conclude that the electroless deposit is the superior material when assessed by salt spray testing, seaside exposure or subjection to nitric acid. Also, resistance to corrosion of electroless nickel is said to increase with increasing phosphorus level. However, unpublished results from International Nickel s Birmingham research laboratory showed that electroless nickel-phosphorus and electrolytic nickel deposits were not significantly different on roof exposure or when compared by polarisation data. [Pg.537]

Electrolyte-sulphuric acid (5% wt.%) plus an inhibitor (0-5kgm ) such as diorthotolyl thiourea, quinoline ethiodide or /3-naphthol quinoline. The temperature should be 75°C, the cathode current density 2000 Am and the time of cathodic polarisation 3 min. The anode should be carbon or lead. If lead anodes are used, lead may deposit on the specimens and cause an error in the weight loss. If the specimen is resistant to nitric acid the lead may be removed by a flash dip in 1 1 nitric acid. Except for this possible source of error, lead is preferred as an anode, as it gives more efficient corrosion product removal. [Pg.1094]

Rinse in water to remove the acid, brush very lightly with a soft bristle brush to remove any loose film, and rinse again. If film remains, immerse for 1 min in concentrated nitric acid and repeat previous steps. Nitric acid may be used alone if there are no deposits. (See comments on this method when used for corroded specimens in the paper by Mercer, A. D., Butler, G. and Warren, G. M., Br. Corros. J., 12, 122 (1977).)... [Pg.1094]

Before use, electrodes must be carefully cleaned to remove any previous deposits. Deposits of copper, silver, cadmium, mercury, and many other metals can be removed by immersion in dilute nitric acid (1 1), rinsing with water, then boiling with fresh 1 1 nitric acid for 5-10 minutes, followed by a final washing with water. Deposits of lead dioxide are best removed by means of 1 1 nitric acid containing a little hydrogen peroxide to reduce the lead to the Pb(II) condition ethanol or oxalic acid may replace the hydrogen peroxide. [Pg.512]

These metals, particularly zinc, appear to react with the platinum in some way, for when they are dissolved off with nitric acid the platinum surface is dulled or blackened. Injury to the platinum can be prevented in these cases by first plating it with copper, and then depositing the metal on this. [Pg.513]

Discussion, Copper may be deposited from either sulphuric or nitric acid solution, but, usually, a mixture of the two acids is employed. If such a solution is electrolysed with an e.m.f. of 2-3 volts the following reactions occur ... [Pg.514]


See other pages where Nitric acid deposition is mentioned: [Pg.746]    [Pg.6]    [Pg.159]    [Pg.384]    [Pg.2427]    [Pg.378]    [Pg.379]    [Pg.191]    [Pg.216]    [Pg.55]    [Pg.384]    [Pg.76]    [Pg.746]    [Pg.6]    [Pg.159]    [Pg.384]    [Pg.2427]    [Pg.378]    [Pg.379]    [Pg.191]    [Pg.216]    [Pg.55]    [Pg.384]    [Pg.76]    [Pg.27]    [Pg.206]    [Pg.498]    [Pg.382]    [Pg.195]    [Pg.21]    [Pg.23]    [Pg.23]    [Pg.24]    [Pg.127]    [Pg.229]    [Pg.408]    [Pg.408]    [Pg.352]    [Pg.146]    [Pg.6]    [Pg.756]    [Pg.512]    [Pg.537]    [Pg.414]    [Pg.509]   


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Acid deposition

Acidic deposition

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