Intermediate colors

Mittel-ding, n. intermediate, cross, -druck, m. medium pressure, -eck, n., -ecke,/. Cryst.) lateral summit, -erz, n. ore of medium value. -Europa, n. Central Europe. mitteleuropSisch, a. Central-European. Mittel-farbe, /. intermediate color secondary color, -fehler, m. average error, mean er-... 

RAW SUGAR The product of sugar cane factories or mills. An intermediate, colored crystalline product resulting from the clarification and evaporation of water from sugar cane stalk juice. 

CdjPj and CdjAs are low band gap semiconductors (0.5 and 0.1 eV, respectively). The bulk materials are black and start to absorb in the infrared. These materials have been prepared as colloids in alkaline solution by precipitation of Cd with phosphine and arsine Depending on the conditions of preparation, particles of different sizes (between about 2 and 10 nm) were obtained, which could also be recovered in the solid state after evaporation of the solvent. The color of these materials ranged from black to colorless with decreasing particle size, with all kinds of intermediate colors in the visible. 

The presence of protonated amine (AAOMe-HX X = Cl TFA CF3S03) in the reaction mixtures results in loss of the red intermediate color and eliminates the small amount of side-product produced in its absence (cf. Section III,C). Only one kinetic process is now seen, but the rate of dipeptide production is little changed from that ob-... 

These are the two colors measured by the image sensor. In practice, intermediate colors also occur at the boundary of the patch however, this shall not be our concern here. This input stimulus is processed by a color constancy algorithm. In the following text, we will calculate the output color for each algorithm in turn. 

Intermediate Colors. There are six intermediate colors, each made by combining adjoining primary and secondary colors in equal amounts. The intermediate colors are red-orange, red-violet, blue-violet, blue-green, yellow-green, and yellow-orange. 

Intermediate Colors. Third in importance are the six remaining colors on the color wheel, which are combinations of equal amounts of the colors on either side of them on the wheel ... 

Students will learn the proper procedure for mixing secondary and intermediate colors. 

Paint in the secondary and intermediate colors by mixing appropriate primary and secondary colors. 

Proceed by painting the next set of shapes, outward from the center, in the next color of the color wheel, an intermediate color. NOTE No two shapes sharing a common side should be painted the same color. 

Paint the next set of shapes in the appropriate intermediate color. 

A computer-calculated molecular representation that uses colors to show the charge distribution in a molecule. In most cases, the EPM uses red to show electron-rich regions (most negative electrostatic potential) and blue or purple to show electron-poor regions (most positive electrostatic potential). The intermediate colors orange, yellow, and green show regions with intermediate electrostatic potentials, (p. 10)... 

The indicator will thus consist of equal amounts of the ionized and unionized forms, and hence wull show its exact intermediate color, when the hydrogen ion activity, or concentration, is equal to the indicator constant. 

Determination of pH With Buffer Solutions.—If a series of buffer solutions of known pH, which must lie in the region of the pH to be determined, is available the estimation of the unknown pH is a relatively simple matter. It is first necessary to choose, by preliminary experiments, an indicator that exhibits a definite intermediate color in the solution under examination. The color produced is then compared with that given by the same amount of the indicator in the various solutions of known pH. In the absence of a salt error, to which reference will be made later, the pH of the unknown solution will be the same as that of the buffer solution in which the indicator exhibits the same color. Provided a sufficient number of solutions of known pH are available, this method can give results which are correct to about 0.05 pH unit. 

In 1916, Henri Bordier reported on the action of light on iodine and starch iodide in water. He observed that dilute solutions of 10% tincture of iodine (pale yellow) and three drops of 10% tincture of iodine plus a little starch paste (blue) were both decolorized after a few hours of exposure to light (13) or a few minutes exposure to X rays (14) and that yellow glass had no effect on the reaction. Both solutions were faded by exposure to light and the protective ability of any colored glass could be judged using these solutions by its intermediate color. Thus, we have one of the first... 

If one form is much more intensely colored than the other, the intermediate color is attained at a potential somewhat removed from j°. ... 

Neutral red or phenol red will show an intermediate color,... 

The slight temperature effect was confirmed further by observing the behavior of methyl red in ammonium chloride solutions. Noyes (p. 21) has reported that the dissociation constant of ammonia is independent of temperature. Since Kw increases 100 times, the pH of the boiling solution must be considerably decreased, and the color of solution must of necessity be shifted to the acid side. This was confirmed experimentally as follows. Several drops of methyl red added to a 0.2 N ammonium chloride solution showed an intermediate color (pH = 5.1). Boiling produced a much more intense red, although not quite the color of methyl red at a pH of 4.2. After cooling, the color corresponded to the original pH. 

Small amounts of water. We have already seen in Chapter Four ( 5) that the dissociation constant of an acid in alcohol is increased strikingly when water is added. It is of equal interest to know how a trace of water will change the color of an indicator which is exhibiting an intermediate color in a given acid-base solution in pure alcohol. The influence of water is determined by the nature of the particular acid-base system contained in the alcoholic solution. 

The variation of the sensitivity of indicators induced by the presence of alcohol has been studied more quantitatively in the following manner. Into separate beakers were pipetted 25 c.c. of conductivity water and of the alcohol solution under investigation. The same quantity of indicator solution was added to both solutions. The aqueous medium was treated with a known volume of acid or alkali which was sufficient to produce a distinct intermediate coloration. Then, from a microburette, enough acid or alkali was pipetted into the alcoholic solution to produce a color of equal intensity. These experiments were performed at 11-12°. 

It is peculiar that the effect of increasing temperature on the color of an indicator in alcoholic solution is the opposite of that found in aqueous solutions. Whereas in aqueous solution an acid indicator like phenolphthalein becomes more acid sensitive when warmed, we find also that a weakly alkaline alcoholic solution of the indicator assumes a more intense red color at a higher temperature. This reversal is observed also with methyl orange. Thus an aqueous solution of the latter indicator, previously treated with strong acid to obtain an intermediate color, turns yellow upon being warmed, whereas an alcoholic solution similarly prepared becomes a more intense red. 

Measurements should be carried out with two different indicators, unless routine analyses are involved. When nothing at all is known of the acidity of the solution, the approximate pH must first be found in order to permit a choice of proper indicators. Of course only those indicators may be used which impart a distinct intermediate color to the unknown solution. An indicator is of no value if its color in the unknown solution is due to the pure acid or pure basic form. The preliminary examination for acidity may be performed with the use of various indicator papers such as congo, litmus, phenolphthalein, and turmeric papers, or by treating small portions of liquid (on a spot plate) with various indicators. If it happens, for example, that a solution remains colorless in the presence of phenolphthalein and is alkaline towards methyl orange, its pH must lie between 8 and 4.5. Should further tests show the unknown to be alkaline also to methyl red, we would know that the pH being measured lies between 6 and 8, and that a suitable indicator could be chosen from the group which includes bromthymol blue, phenol red, neutral red, and cresol red. Universal indicators are especially useful for making such estimates of pH values. 

Thymol blue Isobutyl alcohol red at pH = 1 yellow at pH = 4 intermediate colors between pH s 1-4. 

Bromphenol blue Solvent yellow at pH = 3 blue at pH = 6 intermediate colors between 3 and 6. 

Coal tar crudes, derived from coal tar distillation Coal tar distillates Coal tar intermediates Color lakes and toners Color pigments, organic except animal black and bone black... 

Record distinct red color as methyl red +, distinct yellow color as methyl red —, and intermediate colors as . 

Figure lb shows the electrostatic potential at the small molecule. The potential ranges from -100 kcal/mole per unit electron charge (red) to 0 kcal/mole per unit electron charge (green) with intermediate values shaded intermediate colors (e.g., yellow at about -50 kcal/mole per unit electron charge). The potential indicates that there are two positions where positive charge would be desirable position 16 and position 23. There are many... 

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