Barium chlorate

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Wikipedia

Barium chlorate
Names
IUPAC name
Barium dichlorate
Other names
Chloric acid, barium salt
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.033.404 Edit this at Wikidata
EC Number
  • 236-760-7
RTECS number
  • FN9770000
UNII
UN number 1445
  • InChI=1S/Ba.2ClHO3/c;2*2-1(3)4/h;2*(H,2,3,4)/q+2;;/p-2 checkY
    Key: ISFLYIRWQDJPDR-UHFFFAOYSA-L checkY
  • InChI=1/Ba.2ClHO3/c;2*2-1(3)4/h;2*(H,2,3,4)/q+2;;/p-2
    Key: ISFLYIRWQDJPDR-NUQVWONBAT
  • [Ba+2].[O-]Cl(=O)=O.[O-]Cl(=O)=O
Properties
  • Ba(ClO3)2 (anhydrous)
  • Ba(ClO3)2·H2O (monohydrate)
Molar mass
  • 304.22 g⋅mol−1 (anhydrous)
  • 322.24 g⋅mol−1 (monohydrate)
Appearance white solid
Density 3.18 g/cm3 (monohydrate)
Melting point
  • 120 °C (248 °F; 393 K) (monohydrate, decomposes to anhydrous)
  • 413.9 °C (777.0 °F; 687.0 K) (anhydrous, decomposes)[1]
  • 20.3 g/100g (0 °C (32 °F; 273 K))
  • 33.8 g/100g (20 °C (68 °F; 293 K))
  • 84.8 g/100g (80 °C (176 °F; 353 K))
  • 105 g/100g (100 °C (212 °F; 373 K))[1]
−87.5×10−6 cm3/mol
Hazards[2]
GHS labelling:
GHS03: OxidizingGHS07: Exclamation markGHS09: Environmental hazard
Danger
H271, H302, H332, H411
P210, P220, P221, P261, P264, P270, P271, P273, P280, P283, P301+P312, P304+P312, P304+P340, P306+P360, P312, P330, P370+P378, P371+P380+P375, P391, P501
NFPA 704 (fire diamond)
[3]
NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazard OX: Oxidizer. E.g. potassium perchlorate
3
0
0
OX
0.5 mg/m3 (TWA)
Lethal dose or concentration (LD, LC):
500.1 mg/kg
1.5 mg/L (4h, dust/mist)
NIOSH (US health exposure limits):
PEL (Permissible)
 0.5 mg/m3 (Vacated)
IDLH (Immediate danger)
 50 mg/m3
Safety data sheet (SDS) Fisher Scientific[3]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Barium chlorate, Ba(ClO3)2, is the barium salt of chloric acid. It commonly exists as the monohydrate, Ba(ClO3)2·H2O. It is a white crystalline solid, and like all soluble barium compounds, toxic. It is sometimes used in pyrotechnics to produce a green colour. It also finds use in the production of chloric acid.

Reactions

Synthesis

Barium chlorate can be produced through a double replacement reaction between solutions of barium chloride and sodium chlorate:

BaCl2 + 2 NaClO3 → Ba(ClO3)2 + 2 NaCl

After concentrating and cooling the resulting mixture, barium chlorate precipitates. This is perhaps the most common preparation, exploiting the lower solubility of barium chlorate compared to sodium chlorate.[citation needed]

The above method does result in some sodium contamination, which is undesirable for pyrotechnic purposes, where the strong yellow colour of sodium can easily overpower the green of barium. Sodium-free barium chlorate can be produced directly through electrolysis:[4]

BaCl2 + 6 H2O → Ba(ClO3)2 + 6 H2

It can also be produced by the reaction of barium carbonate with boiling ammonium chlorate solution:[5]: 314–315 

2 NH4ClO3 + BaCO3 → Ba(ClO3)2 + 2 NH3 + H2O + CO2

The reaction initially produces barium chlorate and ammonium carbonate; boiling the solution decomposes the ammonium carbonate and drives off the resulting ammonia and carbon dioxide, leaving only barium chlorate in solution.

Decomposition

At the melting point, barium chlorate alone will decompose to barium chloride and oxygen:[1]

Ba(ClO3)2 → BaCl2 + 3 O2

Commercial uses

Pyrotechnics

When barium chlorate is used as an oxidizer in a mixture with any fuel, it burns to produce a vibrant green light. It is one of the only oxidizers which can be used in a binary mixture to produce a high quality color; simple mixtures of Ba(ClO3)2 and shellac are sufficient to produce a high quality green.[1] It was falling out of use by the mid 20th century, but when it was used more heavily in pyrotechnics, purely barium chlorate oxidized star formulas were reserved for higher quality exhibition devices due to the high cost and the high percentage of barium chlorate in said formulas.[6]

Pure barium chlorate explodes from strong impact but is not easily detonable otherwise.[1] There is at least one published report of self-ignition of wet stars drying in the sun.[7] Because of the price and the decline in the use of chlorates in general, modern greens are more commonly produced with barium nitrate or barium carbonate and a chlorine donor or high-chlorine oxidizer.[6][1]: 216, 218–9, 226 

Chloric acid

Barium chlorate is sometimes used to produce highly pure chloric acid, which can then be used for production of other pure chlorates.[5]: 312–313 

Toxicity

Barium chlorate is dangerous to human health, causing severe acute effects after high exposure. At lower levels, it is irritating to the skin, nasal passages, and throat, and can cause nausea, vomiting, diarrhea, and abdominal pain. At high levels it may cause methemoglobinemia, a condition where the blood can no longer carry sufficient oxygen. This results in a range of effects from dizziness and lightheadedness to trouble breathing, collapse, and death depending on exposure level. It may also cause tremors, seizures, muscle twitching, and irregular heartbeat.[8]

As a soluble heavy metal salt it has the potential to cause heavy metal poisoning and effects such as kidney damage from long term low level exposures that do not produce immediate symptoms. It may also cause bright spots in the lungs in chest x-rays, a benign condition known as baritosis.[8]

Environmental Hazard

It is very harmful to aquatic organisms if it is leached into bodies of water.[9] It may be necessary to dispose of this compound as hazardous waste, depending on local and or federal laws.[8]

References

  1. 1 2 3 4 5 6 Shimizu, Takeo (1991). Fireworks: the art, science, and technique (3rd ed.). Austin, Tex., U.S.A: Pyrotechnica Publications. pp. 103–4. ISBN 0929388054.
  2. ↑ Sigma-Aldrich Co., Barium chlorate. Retrieved on 6 December 2024.
  3. 1 2 "SDS - Barium Chlorate". fishersci.com. Thermo Fisher Scientific. 30 March 2024. Retrieved 3 November 2025.
  4. ↑ Perigrin, Tom. "Barium Chlorate". GeoCities. Archived from the original on 30 October 2007. Retrieved 22 February 2007.
  5. 1 2 Brauer, Georg; Schmeisser, M. "5. Chlorine, Bromine, Iodine". In Riley, Reed F. (ed.). Handbook of Preparative Inorganic Chemistry (2nd ed.). New York, London: Academic Press. pp. 314–315. ISBN 9780121266011. Retrieved 6 December 2024.
  6. 1 2 Weingart, George W. Pyrotechnics (2nd ed.). pp. 5, 67, 133, 146. Retrieved 3 November 2025. Barium chlorate: This is a better salt for making green fire and gives a very beautiful emerald color. However, its high cost, i.e., about 30¢ a pound [note: barium nitrate is listed at 5-7 cents/lb on the same page] prevents its use except in exhibition work. It is also rather sensitive and easily decomposed and great care must be exercised in handling it.
  7. ↑ B., Bill (2000). "Pyros Beware the Month of June". In Drewes, Jack; Drewes, Dorothy (eds.). The Best of AFN IV. Dingman's Ferry, PA: American Fireworks News. p. 77. ISBN 0-929931-15-7. A tray of green stars made with barium nitrate, barium chlorate, red gum and dextrin ignited while wet at high noon at my plant. Temperature was 75°F and the stars were drying directly in the sun. ... I've been using this formula for over 30 years.
  8. 1 2 3 "Barium Chlorate" (PDF). Right to Know Information. New Jersey Department of Health and Human Services. August 2001 [Original revision published 1986].
  9. ↑ "ICSC 0613 - Barium Chlorate". INCHEM. ILO & WHO: INCHEM. 2021.