Kromátok

Kromátok is a term referring to chemical compounds containing the chromate ion, which has the formula CrO₄²⁻. These compounds are typically salts of chromic acid and are characterized by the presence of chromium in its +6 oxidation state. Chromate salts are often brightly colored, with yellow, orange, and red being common hues, due to the electronic transitions within the chromate ion.

Many important industrial chemicals are chromates. For example, lead chromate (PbCrO₄) is a vibrant yellow pigment historically used in paints and ceramics, though its use has declined due to lead toxicity concerns. Sodium chromate (Na₂CrO₄) and potassium chromate (K₂CrO₄) are soluble in water and are used in various applications, including dyeing, printing, and as corrosion inhibitors.

Chromate compounds are known for their strong oxidizing properties. This characteristic makes them useful in applications such as metal surface treatment, where they are used for passivation and to improve paint adhesion. They are also employed in tanning leather and in the production of pigments and dyes.

However, many chromate compounds, particularly those containing hexavalent chromium, are toxic and carcinogenic. Exposure can occur through inhalation or skin contact, leading to health problems affecting the respiratory system, skin, and kidneys. Due to these health and environmental concerns, the use and disposal of chromate compounds are strictly regulated in many parts of the world. Research continues to explore safer alternatives for many of the traditional applications of chromates.