arsenic trioxide(redirected from Arsenous acid)
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arsenic trioxide[′ärs·ən·ik ‚tri′äk‚sīd]
As2O3 A toxic compound, slightly soluble in water; octahedral crystals change to the monoclinic form by heating at 200°C; occurs naturally as arsenolite and claudetite; used in small quantities in some medicinal preparations. Also known as arsenic oxide; arsenious acid.