Chromotropic acid

Chromotropic Acid

Chromotropic acid chemical structure

Chromotropic acid is a chemical compound with the molecular formula C7H5NO6S. It is also known as 2,7-dihydroxynaphthalene-3,6-disulfonic acid and is commonly used as a reagent in analytical chemistry. Chromotropic acid is a versatile compound that exhibits various properties, making it useful in different applications.

History

Chromotropic acid was first synthesized by German chemist Carl Graebe in 1873. He discovered that the compound could be obtained by the oxidation of naphthalene-1,5-disulfonic acid. Since then, chromotropic acid has been extensively studied and utilized in various scientific fields.

Properties

Chromotropic acid is a yellow crystalline powder that is soluble in water. It has a strong affinity for metals, particularly transition metals, and forms stable complexes with them. The compound is highly sensitive to light and heat, and its color changes upon exposure to these factors. This property makes chromotropic acid useful in colorimetric analysis.

Applications

Analytical Chemistry

Chromotropic acid is widely used in analytical chemistry as a reagent for the determination of various metals. It forms colored complexes with metals such as iron, copper, and vanadium, allowing for their quantification. The colorimetric method using chromotropic acid is simple, sensitive, and widely employed in laboratories.

Organic Synthesis

Chromotropic acid is also utilized in organic synthesis as a versatile building block. It can be used to introduce functional groups, such as sulfonic acid and hydroxyl groups, into organic molecules. Additionally, chromotropic acid derivatives have been employed as dyes and pigments in the textile and printing industries.

Safety Considerations

Chromotropic acid is considered to be a hazardous substance and should be handled with caution. It may cause skin and eye irritation upon contact. Inhalation or ingestion of the compound should be avoided, as it can lead to respiratory and gastrointestinal issues. Proper protective measures, such as gloves and goggles, should be used when working with chromotropic acid.

See Also

• Analytical chemistry
• Organic synthesis
• Colorimetric analysis