Acid Orange 12 is orange-red to yellow brown powder. Colloid solution was orange. In concentrated sulfuric acid yellow, yellow diluted solution of partial dissolution. Acid Orange 12 in concentrated nitric acid in golden yellow, orange-red solution was diluted. Acid Orange 12, no change in the concentration of hydrochloric acid, diluted orange precipitate. Acid Orange 12 in the partial dissolution of concentrated sodium hydroxide solution was orange-red, the color change after dilution.