Barium chlorate

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

Barium chlorate

Names
IUPAC name Barium dichlorate
Other names Chloric acid, barium salt
Identifiers
CAS Number	13477-00-4 Y
3D model (JSmol)	Interactive image
ChemSpider	24273 Y
ECHA InfoCard	100.033.404
EC Number	236-760-7
PubChem CID	26059
RTECS number	FN9770000
UNII	GRW9DUG818
UN number	1445
CompTox Dashboard (EPA)	DTXSID60890702
InChI InChI=1S/Ba.2ClHO3/c;2*2-1(3)4/h;2*(H,2,3,4)/q+2;;/p-2 Y Key: ISFLYIRWQDJPDR-UHFFFAOYSA-L Y InChI=1/Ba.2ClHO3/c;2*2-1(3)4/h;2*(H,2,3,4)/q+2;;/p-2 Key: ISFLYIRWQDJPDR-NUQVWONBAT
SMILES [Ba+2].[O-]Cl(=O)=O.[O-]Cl(=O)=O
Properties
Chemical formula	Ba(ClO3)2
Molar mass	304.23 g/mol
Appearance	white solid
Density	3.18 g/cm3, solid
Melting point	413.9 °C (777.0 °F; 687.0 K) (decomposes)
Solubility in water	27.5 g/100 ml (20 °C)
Magnetic susceptibility (χ)	−87.5·10−6 cm3/mol
Hazards[1]
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H271, H302, H332, H411
Precautionary statements	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 0 3 OX
Lethal dose or concentration (LD, LC):
LD50 (median dose)	500.1 mg/kg
LC50 (median concentration)	(4h) 1.5 mg/l - dust/mist
NIOSH (US health exposure limits):
PEL (Permissible)	0.5 mg/m3 (Vacated)
IDLH (Immediate danger)	50 mg/m3
Safety data sheet (SDS)	Barium Chlorate MSDS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

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:^[2]

BaCl₂ + 6 H₂O → Ba(ClO₃)₂ + 6 H₂

It can also be produced by the reaction of barium carbonate with boiling ammonium chlorate solution:^{[3]: 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.

The green seen in this firework is produced by barium chlorate and barium nitrate

Decomposition

When exposed to heat, barium chlorate alone will decompose to barium chloride and oxygen:

Ba(ClO₃)₂ → BaCl₂ + 3 O₂

Chloric acid

Barium chlorate is sometimes used to produce chloric acid.^{[3]: 312–313}

Commercial uses

When barium chlorate is heated with a fuel, it burns to produce a vibrant green light, which is also a flame test for the presence of bariom ions. Because it is an oxidizer, a chlorine donor, and contains a metal ion, this compound produces a distinctive green colour.^{[citation needed]} However, due to the instability of all chlorates to sulfur, acids, and ammonium ions, chlorates have been banned from use in class C fireworks in the United States. Therefore, more and more firework producers have begun to use more stable compounds such as barium nitrate and barium carbonate.^[4]

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.^[5]

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.^[5]

Environmental Hazard

It is very harmful to aquatic organisms if it is leached into bodies of water.^[6] It may be necessary to dispose of this compound as hazardous waste, depending on local and or federal laws.^[5]