Chromicity definition

Chromic hydroxide, Cr(OH)3, is a compound with low solubility in water. It is usually hydrated and does not have the definite composition represented by the formula. It is quite soluble either in strong acid or strong base. 

Give a definition of oxidation and reduction. Consider two examples, (a) the action of KMnCh with H2S03, and (b) the action of K2Cr207 with HC1. For both of these cases write equations according to the oxide method as outlined in Question 1, under Preparation 64, Chromic Alum. Also write the equations according to the valence method as outlined in Question 3 under the same preparation. 

In few cases has an attempt been made to work out the mechanism of these oxide promoters, the researches having been generally done merely for the purpose of improving the yield of some desired product. Taylor and Williamson s work (see 10) has, however, shown that the addition of chromic oxide to manganous oxide has two definite effects 6 it greatly... 

For reasons which will be evident shortly, it is difficult to lay down definite rules concerning the efficiency of an electrode for anodic oxidation. If the oxidation is brought about by oxygen in an active form or by an oxide of the electrode material, e.g., conversion of chromic to chromate ions and the oxidation of iodate to periodate, the highest effi-... 

Two-phase oxidation (1. 143 2, 71). Brown ei a . have published the definitive paper on the two-phase oxidation of secondary alcohols in diethyl ether with aqueous chromic acid. A number of water-immiscible solvents were examined, but diethyl ether... 

In addition, the toluene must be practically free from olefines or members of the di-olefine series. This demands that the toluene be washed several times with concentrated sulphmic acid to remove these compounds. The laboratory test for olefines consists in agitating some of the toluene with a certain percentage of concentrated sulphuric acid. If olefines are present, the acid layer will acquire a yellow to red color. This color must not be deeper than whatever shade the certain plant has adopted as its standard. The comparison standard colors consist of definite concentrations of solutions of potassium dichromate, chromic acid, etc. 

Photoresponsive polymers so far described change their properties in proportion to the number of photons that they absorb. Thus, when they contain more photo-chromic chromophores, which undergo an isomerization by absorbing a definite number of photons depending on the quantum yield, their properties change more. To make a sensitive photoresponsive polymer, i.e. one which responds more effidently to a fewer photons, we have to introduce an amplification mechanism into the system. A convenient way to achieve this end is to utilize the phase transition of polymers. 

CAS 7738-94-5 EINECS/ELINCS 231-801-5 Synonyms Chromic (VI) acid Definition Exists only in solution Empirical HjCrO,... 

SEM/EDX analysis of the stone revealed the composition as chromic oxide. The petrographic techniques were unable to show definitive results as to the composition. However, through the use of reference materials combined with an experienced microscopist the composition of the stone can be identified. The source of the stone could be either chromium metallic contaminant or unmelted colorant. 

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