Direkt gelbe R

　Brown powder. It is red and only yellow to water to dissolve , dissolve dissolving finely and plainly a little , does not dissolve in other organic solvents . Dark dark red in the dense sulphuric acid, turn dark yellow after diluting (have brown that is precipitated sometimes); Dissolve black partly in the dense hydrochloric acid; Turn olive colour to dissolve partly yellowly and brownly in the dense nitric acid. Aqueous solution its add 10% sulphuric acid turn dark slightly , add strong hydrochloric acid getting yellow to present olive , add strong NaOH liquid present money orange precipitate. Meet color light simply green copper , meet color light slightly red and dark iron , meet zinc and ammonia become pale yellow and getting orange. This product has stronger decreasing function photosensitivly and fragily