Chemical Properties
Barium chromate is a heavy, yellow powder(s); rhomb, monoclinic; prepared from BaCl2 and Na2CrO4 solutions, followed by filtering resulting precipitate; used in safety matches, as a corrosion inhibitor.[MER06] [HAW93]
Physical properties
Yellow orthorhombic crystal; density 4.50 g/cm
3; darkens on heating; insoluble in water and organic solvents; dissolves in mineral acid with decomposition.
Uses
Barium chromate has been found to be useful in many capacities. It is an oxidizing agent, making it useful as a burn rate modifier in pyrotechnic compositions. It is especially useful in delay compositions such as delay fuses. Barium chromate is used as a pigment, oxidizing agent, colorant in glass, and sulfate scavenger in chromium electroplating baths, ceramics, and porcelain. It acts as a corrosion inhibitor in jointing pastes and metal primers. Further, it is used in fuses, safety matches, ignition control devices and high-temperature batteries. In addition to this, it is used as a carrier for the chromium ions and useful as a burn rate modifier in pyrotechnic compositions. It is involved as a catalyst in the alkane dehydration reaction.
Application
Barium chromate is an oxidizing chemical compound composed of the elements barium and chromium. It is a pigment almost entirely in anticorrosion jointing pastes to prevent electro-chemical corrosion at junctions of dissimilar metals; some use in artists' colors and in coloring glass, ceramics, porcelain. Also used in metal primers, pyrotechnic compositions.
Preparation
Interaction of barium chloride and sodium chromate. The precipitate is washed, filtered and dried.
BaCl2+Na2CrO4→BaCrO4↓+2NaCl
Hazard
Confirmed carcinogen.
Safety Profile
Confirmed human
carcinogen. A poison. Mutation data
reported. Reacts vigorously with reducing
materials. See also BARIUM
COMPOUNDS (soluble) and
CHROMIUM COMPOUNDS. Used in
pyrotechnics and as an explosive initiator.
