Acidic soft water

Goldfish, Carasslusauratus, embryos, through day 4 posthatch Boric acid Soft water... 

Juveniles exposed to full-strength agricultural drainwater from San Joaquin Valley, California, for 28 days. Drainwater had 48.8 (44-53) mg B/L Leopard frog, Ranapipiens, embryos, through day 4 posthatch Boric acid Soft water 13 mg B/L 130 mg B/L Hard water 22 mg B/L 135 mg B/L Borax Soft water 5 mg B/L 47 mg B/L Hard water 3 mg B/L 54 mg B/L... 

Reader, J. P, N. C. Everall, M. D. J. Sayer, and R. Morris. 1989. The effects of eight trace metals in acid soft water on survival, mineral uptake and skeletal calcium deposition in yolk-sac fry of brown trout, Salmo trutta L. J. Fish. Biol. 35 187-198. 

Waring, C.P., J.A. Brown, J.E. Collins and P. Prunet. Plasma prolactin, cortisol and thyroid responses of brown trout (Salmo trutta) exposed to lethal and sublethal aluminum in acidic soft waters. Gen. Comp. Endocrinol. 102 337-385, 1996. 

The desire for and achievement of soft water for domestic use has sparked a rather heated health debate. Soft water is usually acidic and contains Na ions in the place of di- and trivalent metal ions. An increased intake of Na is known to be related to heart disease. The acidic soft water is also more likely to attack metallic pipes, joints, and fixtures, resulting in the dissolution of toxic ions such as One way to avoid sodium ions in drinking... 

The theory predicts high stabilities for hard acid - hard base complexes, mainly resulting from electrostatic interactions and for soft acid - soft base complexes, where covalent bonding is also important Hard acid - soft base and hard base - soft acid complexes usually have low stability. Unfortunately, in a quantitative sense, the predictive value of the HSAB theory is limited. Thermodynamic analysis clearly shows a difference between hard-hard interactions and soft-soft interactions. In water hard-hard interactions are usually endothermic and occur only as a result of a gain in entropy, originating from a liberation of water molecules from the hydration shells of the... 

Carboxylate, sulfonate, sulfate, and phosphate ate the polar, solubilizing groups found in most anionic surfactants. In dilute solutions of soft water, these groups ate combined with a 12—15 carbon chain hydrophobe for best surfactant properties. In neutral or acidic media, or in the presence of heavy-metal salts, eg, Ca, the carboxylate group loses most of its solubilizing power. 

The sodium soaps of fatty acid form calcium soaps of such low solubdity that they act as their own budders. Initial soap additions precipitate the calcium ion and the soap added thereafter functions in soft water. At high temperatures, the calcium soaps are relatively soluble compared to calcium tripolyphosphate. Thus sodium tripolyphosphate (STEP) can budd (revert) soaps in a hot water wash. However, at low temperatures the relative affinity of STEP for calcium decreases so that STEP cannot budd soaps in a cold water wash. 

Some of the worst corrosive effects in soft waters are attributed to a rather wide group of organic acids abstracted from peat and mosses, sometimes called peaty acids. Such waters have low pH values and are often discoloured. They affect ferrous metals appreciably and also attack lead and... 

Brass water fittings give no trouble except that dezincification may occur in acid waters or waters of high chloride content, especially when hot. This dezincification has three effects. Firstly, the replacement of brass by porous copper may extend right through the wall of the fitting and permit water to seep through. Secondly, the zinc which is dissolved out of the brass may form very voluminous hard corrosion products and eventually block the waterway —this is often the case in hot soft waters. Thirdly, and often the most important, the mechanical properties of the brass may deteriorate. For instance, a dezincified screwed union will break off when an attempt is made to unscrew it and a dezincified tap or ball-valve seat is readily eroded by the water. 

Problems with heating coils Internal coil corrosion Note corrosion debris is green hydrated copper carbonate Cu[11IC03 nH20 red cuprous oxide Cu20 /ntemal coil deposition Acid corrosion from soft water. Pinhole corrosion from 02 and C02. Erosion corrosion over 6 ft/s flow. Hard water scale from hard water. 

Acids are added to soft drinks for extra bite. The primary acid used in colas is phosphoric acid, while the one used in citrus-flavored drinks is usually citric acid. Carbonated water (water that has the gas carbon dioxide dissolved in it under pressure) is also mildly acidic (it is chemically carbonic acid, H2C03). 

Carboxylic acids with one acid group are known as monobasic acids while those with two acid groups are dibasic acids. All acids with more than one acid group are in the class of polybasic acids. The simplest organic acid, formic acid, is responsible for the irritation of bee and ant stings. Vinegar is a 5% solution of acetic acid in water. The acetic acid is responsible for the characteristic sour taste. Citric acid, found in citrus fruits and used in soft drinks, is a tribasic acid with three carboxylic acid groups. The dibasic acid, adipic acid, is a major component of nylon. 

The kinetics, products, and stereochemistry of the addition of HC1, HBr, and HI to propiolic acid in water have been studied.28 The addition is predominantly trans to give the cz s-3-haloacrylic acid. Both the rate of addition and the selectivity giving trans-addition increase with the nucleophilicity of the halide in water (i.e., I- > Br > Cl-). The order of reactivity is also consistent with the order of the softness of the nucleophiles. The reaction is first order in propiolic acid and the halide anion. It was proposed that the addition involves two mechanistic pathways a major /ra/z.v-addition via a transient carbanion formed with specific geometry and a minor cO-addition process (Scheme 10.2). 

Application of ion exchange refining to the process for the manufacture of dextrose may be understood from the following description of such a process. Triple-washed starch is diluted with ion-free water to the desired concentration and is acidified with a definite quantity of mineral acid such as hydrochloric or sulfuric. It is desirable that the acidified starch slurry be held for at least thirty minutes in order to permit an effective equilibrium acidity to be reached. The starch slurry may contain a quantity of soft water salts which consume acid, and since this consumption is variable, the acidity is checked and adjusted to the desired level following the holding period. The conversion is then carried out at elevated temperature and under pressure for a period sufficient to yield maximum dextrose. The conversion may be carried out batchwise in an autoclave, or continuously. 

Soft Water Add very slowly, mix well SpG 20/20C 0.92 pH 9.30 Recommended Dilutions As necessary Applications Degreaser Formula S-112 Acid/Solvent Cleaner 45.00... 

Groundwater-inflow rates as calculated by the solute and isotope mass-balance methods for several northern Wisconsin lakes are listed in Table I. Dissolved calcium was used as the solute tracer because it is the constituent whose concentration differs the most between groundwater and precipitation, the two input components to be separated by the method. In addition, calcium is nearly conservative in the soft-water, moderately acidic to cir-cum-neutral lakes in northern Wisconsin. Results from the two methods agree relatively well, except for Crystal Lake, where groundwater-flow reversals are frequent. 

Attention has been focused recently on sedimentary microbial reduction of sulfate. This process neutralizes atmospheric sulfuric acid deposited into soft-water lakes (8-10) through the production of two equivalents of alkalinity per mole of sulfate reduced (11). 

Calcium, Ca, at wt 40.08 silvery- wh, soft metal which must be kept in tightly stoppered bottles d 1, 578 at 15° mp 810° sublimes below its mp sol in acids decomposes water liberating hydrogen gas. Can be prepd by electrolyzing molten Ca chloride(Refs 1,2,3 5). Its toxicity is discussed in Ref 4. Some of its salts were proposed for use in smoke producing compns (Ref 6)... 

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