Fuming

Name:
Fuming
Detailed information:
A characteristic of some highly active liquids that evolve visible smokelike emanations on contact with air. Most familiar are the forms of nitric and sulfuric acids designated as fuming. These are not pure, concentrated acids; low percentages of nitrogen dioxide and water are present in fuming nitric acid, and fuming sulfuric acid contains sulfur trioxide. Hydrofluoric acid (a mixture of hydrogen fluoride and water) also fumes. Pure compounds in which fuming occurs are fluosilicic acid and hydrazine.