Ultramicroscopic defects

Very fine, dense powder with a light brown, coffeelike color reacts with dil. HCl to give chlorine. Its physical state, characterized by small particle size, lattice defects and occlusions of admixtures which prove to be amorphous and on x-ray analysis are recognizable under an ultramicroscope [6], causes an extraordinary high chemical activity. Especially useful in dehydrogenation of aromatic dihydroxy compounds to the correspondii ... 

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