chromic

Chromic is an adjective derived from the Greek chroma, meaning color. In chemistry, chromic refers to chromium and to compounds where chromium is in higher oxidation states, notably +6. The term appears in names such as chromic acid (H2CrO4), chromates (CrO4^2−), and dichromates (Cr2O7^2−). Common reagents include potassium dichromate (K2Cr2O7) and chromium trioxide (CrO3). Many chromates are yellow and dichromates orange; solutions of chromic acid are strongly colored.

In chemistry, chromic compounds are known for being powerful oxidizing agents and have long been used in organic synthesis, for example as oxidants in the oxidation of alcohols. They have also been employed in various analytical colorimetric tests. The use of chromic reagents has diminished in some areas due to toxicity concerns, with modern methods increasingly substituting for chromic oxidants in many applications.

In industry, chromium salts are used in metal finishing, pigment production, and other processes. Chromium tanning utilizes Cr(III) salts to treat hides, a practice distinct from hexavalent chromium chemistry but commonly discussed under chromium-related technologies. The broader term chromic can thus refer to chromium-containing substances across several sectors.

Safety and environment: hexavalent chromium compounds are toxic and carcinogenic, and exposure controls, handling protocols, and waste treatment are important. Regulatory measures restrict the use of many Cr(VI) compounds, prompting the development and adoption of safer alternatives where feasible.

Chromic materials: beyond chemical salts, chromic also describes materials that change color in response to stimuli (thermochromic, photochromic, electrochromic). Such chromic materials are used in sensors, smart coatings, and display technologies.