Phenylhydrazine is a colourless to slightly brownish liquid at a Room temperature. It starts forming monoclinic prism at a temperature below 15oC. Phenylhydrazine turns Yellow to Dark red in colour upon exposure of Air. Phenylhydrazine is miscible in ethanol, diethyl ether & benzene. Phenylhydrazine is used in the manufacturing of Indoles, which are used in the synthesis of various Intermediates in Dyes & Pharmaceuticals. Phenylhydrazine is also used as a stabilizer.