Thiocyanic acid

Thiocyanic acid is a chemical compound with the formula HSCN. It is a pseudohalogen and an isomer of cyanic acid and fulminic acid. Thiocyanic acid is a weak acid, and it is notable for its tendency to form coordination complexes with transition metals.

History

Thiocyanic acid was first synthesized in the 19th century by chemists who were studying the properties of cyanide. The compound was initially produced by the reaction of hydrogen sulfide with cyanogen chloride.

Properties

Thiocyanic acid is a colorless liquid that has a strong, unpleasant odor. It is highly reactive and can form a variety of different compounds. The acid is a weak Bronsted-Lowry acid, and it can donate a proton to form the thiocyanate anion.

Synthesis

Thiocyanic acid can be synthesized by the reaction of hydrogen sulfide with cyanogen chloride. This reaction produces thiocyanic acid and hydrochloric acid as a byproduct. The reaction can be represented by the following chemical equation:

H2S + ClCN → HSCN + HCl

Uses

Thiocyanic acid is used in the synthesis of a variety of different compounds. It is often used as a reagent in chemical reactions, and it can also be used to produce thiocyanate salts. These salts are used in a variety of applications, including as catalysts in chemical reactions and as precipitating agents in analytical chemistry.

Safety

Thiocyanic acid is a highly reactive compound, and it can cause burns if it comes into contact with the skin or eyes. It is also toxic if ingested or inhaled. Proper safety precautions should be taken when handling thiocyanic acid, including the use of personal protective equipment and adequate ventilation.

See also

• Cyanic acid
• Fulminic acid
• Thiocyanate