Alizarin indicator

Sommelet, 30, 67 Alizarin indicator, 37, 33 Alkylation, of acetylene, 30, 15 of aniline with triphenylcarbinol, 30, 5 of e-caprolactam with dimethyl sulfate,... 

CAS 72-48-0 EINECS/ELINCS 200-782-5 Synonyms Alizarine Alizarine indicator Alizarine red Alizarin red 9,10-Anthracenedione, 1,2-dihydroxy-Anthraquinone, 1,2-dihydroxy- 1,2-Anthraquinonediol Cl 58000 D C Orange No. 15 1,2-Dihydroxyanthraquinone 1,2-Dihydroxy-9,10-anthraquinone Mordant red 11 Pigment red 83 Turkey red Classification Aromatic ketone Empirical C14H8O4... 

Alizarin cyanine green F. See Acid green 25 Alizarine. See Alizarin Alizarine blue A. See Acid blue 41 Alizarine cyanine green F. See D C Green No. 5 Alizarine indicator Alizarine red. See Alizarin Alizarin oil. See Sulfated castor oil Alizarin red. See Alizarin Alizurol purple SS. See D C Violet No. 2 Disperse blue 72... 

Other Names Alizarin B Anthraquinone, 1,2-dihydroxy- 1,2-Anthraquinonediol 1,2-Dihydroxy-9,10-anthracenedione l,2-Dihydroxy-9,10-anthraquinone 1,2-Dihydroxyanthraquinone Acid Metachrome Red B Acid Mordant Red B Alizarin Alizarin Red Alizarina Alizarine Alizarine 3B Alizarine B Alizarine Indicator Alizarine L Paste Alizarine Lake Red 2P Alizarine Lake Red 3P Alizarine Lake Red IPX Alizarine NAC Alizarine Paste 20 percent Bluish Ahzarine Red Alizarine Red B Alizarine Red B2 Alizarine Red IP Alizarine Red IPP Alizarine Red L C Ext. Red 62 C.I. 58000 C.I. Mordant Red 11 Certiqual Alizarine D And C Orange Number 15 Deep Crimson Madder 10821 Eljon Madder Mitsui Alizarine B Mordant Red 11 NSC 7212 Turkey Red... 

Plane one drop of the solution upon zireonium-alizarin-S test paper. A yellow eolour on the red paper indicates the presenee of fluoride. 

Alizarin, dihydroxyanthraquinone (indicator) dissolve 0.1 g in 100 mL alcohol pH range yellow 5.5-6.8 red. 

Indicator solutions a number of indicator solutions are listed in this section under the names of the indicators e.g., alizarin, aurin, azolitmin, et al., which follow alphabetically. See also various index entries. 

Rosolic acid, aurin, corallin, corallinphthalein, 4,4 -dihydroxy-fuchsone, 4,4 -dihydroxy-3-methyl-fuchsone (indicator) dissolve 0.5 g in 50 mL alcohol and dilute with water to 100 mL. Salicyl yellow (indicator) see alizarin yellow GG. 

Since the pH changes very rapidly at the equivalence point, from about pH = 10 to about pH = 4, most of the indicators in Figure 18-6 can be used. The main exceptions are alizarin yellow R, bromophenol blue, thymol blue (in its acid range), and methyl violet. 

Indicator alizarin yellow R, yellow at pH = 10.0 and violet at pH = 12.0 The three titration curves are drawn with respect to the same axes in the diagram below. 

The potentiometric method also surpasses the others for speed, simplicity, precision and accuracy as indicated in Table 12.1. Furthermore, it is particularly suited to the continuous monitoring of fluoride levels in drinking water. The spectrophotometric methods are lengthy because of the time required to develop a stable colour (up to 1 hour), the alizarin red-S complex being especially poor in this respect. It was noted, however, that for the three bleaching methods (1-3) the rate of change of absorbance by the blank closely followed that of solutions containing fluoride, i.e. the difference between the blank and a sample absorbance is nearly constant. 

The yield of radioactive D.F.P. from 32P is necessarily small on the semi-micro scale (p. 75) it is better therefore to titrate the fluoride (obtained after the decomposition of D.F.P.) with thorium nitrate, sodium alizarin sulphonate being used as indicator.2 It is necessary, however, first of all, to remove the fluoride by distillation (p. 211). This method gives an accuracy of +1 per cent with 50 mg. of D.F.P. This degree of accuracy on a semi-micro scale3 may be considered fairly satisfactory. 

Perlmutter-Hayman and Shinar (15, 16) have studied by temperature-jump the reactions of bases with different acid-base indicators having intramolecular hydrogen bonds. With Tropaeolin 0, direct attack of the base on the hydrogen bridge predominates according to their interpretation, whereas, for Alizarin Yellow G, the observed relaxation is ascribed chiefly to diffusion controlled reaction between the base and that part of the indicator present in the open form. Thus, data exist that lead one to doubt the generality of statement number 5. 

A range of indicators are available with different end-points are available. Thymol blue and alizarin are diprotic. They change colour over two different ranges. 

Titration with Ba(OH)2 in 50 vol% aqueous methanol using alizarin red S as indicator. 

PROBLEM 16.17 The following acid-base indicators change color in the indicated pH ranges bromthymol blue (6.0—7.6), thymolphthalein (9.4-10.6), and alizarin yellow (10.1-12.0). Which indicator is best for the titration in Problem 16.16 Which indicator is unacceptable Explain. 

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