Sodium chloride estimation

Sodium Chloride [25]. Sodium chloride estimation is based on sodium titration. To 20 ml of a 1 1 mixture of toluene (xylene) isopropyl alcohol, add a 1-ml sample of oil-base mud, stirring constantly and 75 to 100 ml of distilled water. Add 8-10 drops of phenolphthalein indicator solution and titrate the mixture with H SO (N/10) until the red (pink) color, if any, disappears. Add 1 ml of potassium chromate to the mixture and titrate with 0.282N AgNO (silver nitrate, 1 ml = 0.001 g chloride ions) until the water portion color changes from yellow to orange. Then... 

A column of Sephadex of small pore size gives a retention volume of 46.7 ml for a high-molecular-weight polysaccharide, 63.2 ml for sucrose, and 75.7 ml for sodium chloride. Estimate the partition ratios for these three materials. State any assumptions made. 

Figure 12(e) shows the much more complex phase behavior observed when water is mixed with low volatility salts, in this case the sodium chloride-water system at 250 Ivir. " Due to the high critical temperature of sodium chloride, estimated at 3900K and 260 bar, this system is subcritical at SCWO reactor conditions. Figure 12(e) shows an operating line for 10 wt% NaCl at 250 bar. As this brine is heated from ambient temperature, a split into vapor and liquid phases occurs in the vicinity of 400°C, As temperature increases to 450 C. NaCl... 

An indirect estimate of surface tension may be obtained from the change in lattice parameters of small crystals such as magnesium oxide and sodium chloride owing to surface tensional compression [121] however, these may represent nonequilibrium surface stress rather than surface tension [68]. Surface stresses may produce wrinkling in harder materials [122]. 

The excess heat of solution of sample A of finely divided sodium chloride is 18 cal/g, and that of sample B is 12 cal/g. The area is estimated by making a microscopic count of the number of particles in a known weight of sample, and it is found that sample A contains 22 times more particles per gram than does sample B. Are the specific surface energies the same for the two samples If not, calculate their ratio. 

Addition of calcium nitrate solution to a fluoride gives a white precipitate of calcium fluoride, CaFj. If the latter is precipitated slowly, it can be filtered off and weighed to estimate the fluoride. Fluoride can also be determined by the addition of sodium chloride and lead nitrate which precipitate lead chlorofluoride, PbClF. This is filtered off and weighed. 

Principle. An organic compound which contains chlorine is mixed with sodium peroxide and ignited in a closed metal bomb. The chlorine is thus converted to sodium chloride, and after acidification the chloride is estimated by the Volhard volumetric method. Bromine and iodine, when constituents of organic compounds similarly treated, are converted largely into sodium bromate and iodate respectively these ions are therefore subsequently reduced by hydrazine to bromide and iodide ions, and estimated as before. 

Schiesser and Lapidus (S3), in later studies, measured the liquid residencetime distribution for a column of 4-in. diameter and 4-ft height packed with spherical particles of varying porosity and nominal diameters of in. and in. The liquid medium was water, and as tracers sodium chloride or methyl orange were employed. The specific purposes of this study were to determine radial variations in liquid flow rate and to demonstrate how pore diffusivity and pore structure may be estimated and characterized on the basis of tracer experiments. Significant radial variations in flow rate were observed methods are discussed for separating the hydrodynamic and diffusional contributions to the residence-time curves. 

We have seen how to estimate the pH of a solution of a weak acid or base (Chapter 10), but suppose that a salt of the acid or base is also present. How does that salt affect the pH of the solution Suppose we have a dilute hydrochloric acid solution and add to it appreciable concentrations of the conjugate base, the Cl- ion, as sodium chloride. Because the acid is strong, its conjugate base is extremely weak and so has no measurable effect on pH. The pH of 0.10 M HCl(aq) is about 1.0, even after 0.10 mol NaCl has been added to a liter of the solution. Now suppose instead that the solution contains acetic acid to which sodium acetate has been added (the acetate ion, CH jC()2, is the conjugate base of CH COOH). Because the conjugate base of a weak acid is a base, we can predict that adding acetate ions (as sodium acetate) to a solution of acetic acid will increase the pH of the solution. Similarly, suppose we have a solution of ammonia and add ammonium chloride to it. The... 

C12-0101. Brackish water, with a salt content around 0.5% by mass, is found in semiarid regions such as the American southwest. Assuming that brackish water contains only sodium chloride and that the ions form no ion pairs, estimate the osmotic pressure of brackish water at 298 K. 

Estimate the anticipated change in serum sodium concentrations after the infusion of 1 L of 3% sodium chloride in a 75-kg male with a serum sodium of 123 mEq/L (123 mmol/L). 

In patients with peritonitis, hypovolemia is often accompanied by acidosis, so large volumes of a solution such as lac-tated Ringers may be required initially to restore intravascular volume. Maintenance fluids should be instituted (after intravascular volume is restored) with 0.9% sodium chloride and potassium chloride (20 mEq/L) or 5% dextrose and 0.45% sodium chloride with potassium chloride (20 mEq/L). The administration rate should be based on estimated daily fluid loss through urine and nasogastric suction, including 0.5 to 1.0 L for insensible fluid loss. Potassium would not be included routinely if the patient is hyperkalemic or has renal insufficiency. Aggressive fluid therapy often must be continued in the postoperative period because fluid will continue to sequester in the peritoneal cavity, bowel wall, and lumen. 

The chemical method for the determination of the chemical oxygen demand of non-saline waters involves oxidation of the organic matter with an excess of standard acidic potassium dichromate in the presence of silver sulfate catalyst followed by estimation of unused dichromate by titration with ferrous ammonium sulfate. Unfortunately, in this method, the high concentrations of sodium chloride present in sea water react with potassium dichromate producing chlorine ... 

Nickel oxide, NiO, is doped with lithium oxide, Li20, to form Li Ni, xO with the sodium chloride structure, (a) Derive the form of the Heikes equation for the variation of Seebeck coefficient, a, with the degree of doping, x. The following table gives values of a versus log[(l-x)/x] for this material, (b) Are the current carriers holes or electrons (c) Estimate the value of the constant term k/e. 

Pure potassium bromide, KBr, which adopts the sodium chloride structure, has the fraction of empty cation sites due to Schottky defects, ncv/Nc, equal to 9.159xl0-21 at 20°C. (a) Estimate the enthalpy of formation of a Schottky defect, Ahs. (b) Calculate the number of anion vacancies per cubic meter of KBr at 730°C (just below the melting point of KBr). The unit cell of KBr is cubic with edge length a = 0.6600 nm and contains four formula units of KBr. 

The formation energy of Schottky defects in NiO has been estimated at 198 kJ mol-1. The lattice parameter of the sodium chloride structure unit cell is 0.417 nm. (a) Calculate the number of Schottky defects per cubic meter in NiO at 1000°C. (b) How many vacancies are there at this temperature (c) Estimate the density of NiO and hence the number of Schottky defects per gram of NiO. 

The following table gives the values of the fraction of Schottky defects, S/N, in a crystal of NaBr, with the sodium chloride structure, as a function of temperature. Estimate the formation enthalpy of the defects. 

This very approximate model gives reasonable agreement with such disparate materials as iron, quartz and sodium chloride with a 0.14. Alternatively, of course, if we know the melting point, we can obtain an estimate of the elastic modulus. 

Osmolarity of perfusate solution The buffer osmolarity should be standardised to facilitate estimation of Peff values. Generally adjusted to physiological conditions of 290 mOsm/kg. (70 mM phosphate buffer) with 5.4 mM potassium chloride, 48 mM sodium chloride, 35 mM mannitol, and 10 mM D-glucose. Lane et al. [131] demonstrated the effect of hypersomolar perfusion on Tapp of ibuprofen in the in situ rat gut technique. Hypersomolar solutions tended to decrease Peff values, attributable to a reversed solvent drag effect. 

The sodium chloride (NaCl) crystal shows very high absorption and reflectivity in the infrared region, known as the Restrahlen region. The real and imaginary relative dielectric constants at 6000 nm are, respectively, ei = 16.8 and S2 = 91.4. At this wavelength, estimate (a) the refractive index and the extinction coefficient, and (b) the optical density and the reflectivity at normal incidence for a 1 mm thick NaCl sample, (c) If the previous sample is illuminated (at normal incidence) by a beam of intensity Iq at 6000 nm, estimate the intensity of this... 

Fig. 5-30. Potential profile across a compact layer estimated by calculations at various electrode potentials for a mercury electrode in a 03 M sodium chloride solution electrode potential changes fivm No. 1 (a cathodic potential) to No. 6 (an anodic potential), and contact adsorption of chloride ions takes place at anodic potentials. E = electrode potential = zero charge potential x = distance fix>m the interface. [From (3raham, 1947.]...

For 5 M sodium chloride, the same results are obtained and, e.g., k = 4.2 X 10" sec at pH 4.7. (pH values were estimated using a pH meter with glass and calomel reference electrodes. Values recorded are independent of the salt concentration between 1 and 7 M, but depend on the nature of the buffer.)... 

Generally, mn+ estimated from Equation (20.8) by inserting an approximate value of K and neglecting the activity coefficients. Thus, it is possible to obtain tentative values of — (RT/S ) In fC and hence K at various concentrations of acetic acid, sodium acetate, and sodium chloride, respectively. The ionic strength / ... 

The reduction was done essentially as described previously (Robins, 1976). After several washings with 0.9% (w/v) sodium chloride, 0.05 M sodium phosphate, pH 7.4, at 4°C, the stirred demineralized root powder was reduced with 0.71 g sodium borohydride, an estimated one-twentieth of the collagen mass. After one hour, the solution was acidified (pH < 4, pH paper) to inactivate remaining borohydride. Thereafter, the pH was readjusted to 7.5. The solution was centrifuged and the pellets were hydrolyzed by heating for 24 hours at 112°C in 6 M HCl under N2 in bottles with Teflon-sided screw caps. The dark hydrolyzate was paper-filtered, evaporated under reduced pressure at 50°C, and mixed with 5 ml 0.1 M acetic acid. The hydrolyzate was assayed for hydroxyproline. 

Procedure of Analysis. Rate constant can be calculated as a slope of the line plotted right hand side of equation ( ) against time elasped. At first acetyl content is estimated from the ratio of sodium chloride permeability of the deteriorated membrane and the initial by Fig.12. Using the estimated acetyl content, and f2(CA) can be obtained from Fig. 12. Using these values and f ... 

Close-packed spheres occupy 74.04% of a total volume, hence the hard-sphere radius of I" in these 2 1 salts in 2.03 A. Correction for the electrostatic attraction alone would give a monovalent iodide radius of about 2.24, an opposite repulsion-correction for the different co-ordination number would reduce this to about 2.10 A for the monovalent sodium-chloride type (see Appendix). Such values are consistent with our earlier estimates, but incompatible with the electron-density minimum value (4) of 1.94 A. 

Estimate the lattice energy of sodium chloride, using the appropriate data from Appendix F and assuming that the Born exponent is 9. Compare your result with the value given in Eq. 4.8. 

For the gas-measuring device, the submitters used an inverted, calibrated 10-1. bottle, filled with saturated sodium chloride solution, resting in an enamel bucket big enough to hold the volume to be displaced. The checkers used a gas meter. However, the rate of gas evolution can be estimated by using a simple gas bubbler. 

Finely dispersed sodium chloride particles were prepared, their specific area was measured, and their solubility in ethanol at 25°C was studied. It was found that a preparation with a specific area of 4.25 x 105 cm2 g-1 showed a supersaturation of 6.71%. Estimate the radius of the NaCl (p = 2.17 gm cm-3) particles, assuming uniform spheres. Calculate 7 for the NaCl-alcohol interface from the solubility behavior of this sample. 

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