: Highly soluble: 62.5% w/w at 20 ºC ( 68 ºF) 67.5% w/w at 100 ºC (212 ºF)
Bulk Density
: Loose 75 lbs. per cubic foot
Heat of Solution
: Exothermic (24.7 cal./g.; 44.5 BTU/lb.)
Behavior on Heating
: Melts at 197 ºC (387 ºF)
Chemical Characteristics
: to intermediate chromium oxides at slightly higher temperatures.
Chromic acid is a strong acid and oxidizing agent. When neutralized with alkalis, chromic acid forms
dichromate or chromate compounds. In oxidation reactions, the chromium atom is reduced from the
hexavalent to trivalent state.
The major uses of chromic acid are in wood preservation, metal finishing and plating.
Secondary applications include catalyst manufacture and magnetic recording tapes.
Chromic acid is used to produce salt-free CCA type wood preservatives. These preservatives
are combinations of chromium, copper and arsenic. The CCA offers protection from wood
destroying fungi, marine borers, termites, ascomycetes, white rot, dry rot and brown rot.
When treatment is in accordance with American Wood Preservers Association standards, a
clean, odorless, paintable surface is produced which is safe and non-toxic for human use and
is environmentally sound.
The two main types of chromium electroplating are decorative and functional. Decorative
chromium plating is usually applied as a very thin layer to articles that have been nickel
plated and is used for plumbing fixtures, automobile accessories, domestic appliances, etc.,
imparting a bright shiny finish. Functional or “hard” chromium plate is applied in much thicker
layers and gives an extremely hard, corrosion-resistant surface with a low coefficient of
friction. Hard chrome plating finds use in piston rings, engine cylinders, inspection and
cutting tools and metal working machinery. The finish is usually dull. Electrodeposition of
chromium from solutions containing chromic acid is also used in the manufacture of pure
chromium metal for incorporation in creep resistant high temperature alloys.
Chromic acid is used in the anodizing of aluminum. The extremely thin layer of oxide, which
gives aluminum metal its resistance to corrosion, is thickened by anodic oxidization using
chromic acid solution as the electrolyte. The coatings obtained are semi-opaque and gray in
color. They are capable of being dyed to give a very pleasing finish. They also provide a
good base for the application of paint and other organic finishes.
Chromate or dichromate ions are widely used in the metal finishing field to impart corrosion
resistance. Conversion coatings, chromate containing films of oxide, are formed on metal
surfaces by using sodium dichromate, potassium dichromate or chromic acid. Chromic acid
solutions are also used for sealing phosphate coatings applied to iron or steel to improve
their corrosion resistance. Other applications in the metal finishing field include its use for
bright dipping of brass and acid cleaning of aluminum and magnesium.
Chromic acid is a powerful oxidizing agent, which leads to a variety of uses in organic
syntheses and in the bleaching of oils, fats and waxes. Chromic acid is used in the
manufacture of other chromium compounds and as an analytical reagent.
HEALTH AND SAFETY PRECAUTIONS:
Chromic acid is a hexavalent chromium compound, and contact with it, either in the solid or solution form,
should
be avoided. In case of contact, flush thoroughly with water. For eyes, give prolonged irrigation with
water, and get
medical attention immediately.
For detailed information, consult our Material Safety Data Sheet (MSDS), which is available upon
request.
STORAGE:
This product should be stored in a cool, dry place. It is a powerful oxidizing agent and may cause a fire if
it comes in contact with readily oxidizable or combustible matter.
