Strontium oxalate

Strontium oxalate is a compound with the chemical formula SrC₂O₄. Strontium oxalate can exist either in a hydrated form (SrC₂O₄·nH₂O) or as the acidic salt of strontium oxalate (SrC₂O₄·mH₂C₂O₄·nH₂O).^{[5][verification needed]}

Strontium oxalate

Names
IUPAC name Strontium oxalate
Identifiers
CAS Number	814-95-9 Y
3D model (JSmol)	Interactive image
ChemSpider	63140
ECHA InfoCard	100.011.286
EC Number	212-415-6
PubChem CID	69947
UNII	7IAW7E69NI Y
CompTox Dashboard (EPA)	DTXSID80883590
InChI InChI=1S/C2H2O4.Sr/c3-1(4)2(5)6;/h(H,3,4)(H,5,6);/q;+2/p-2 Key: KQAGKTURZUKUCH-UHFFFAOYSA-L
SMILES [Sr+2].[O-]C(=O)C([O-])=O
Properties
Chemical formula	SrC2O4
Molar mass	175.64 g·mol−1
Appearance	White powder
Density	2.08 g/cm3
Melting point	Decomposes above 150 °C (302 °F; 423 K) (monohydrate)[1]
Solubility in water	4.6 mg/100g at 18 °C (64 °F) 5 g/100g at 100 °C (212 °F)[1]
Solubility in Acetic acid	52.6 mg/100g (3.5% acid) 870 mg/100g (23% acid)[2][page needed]
Hazards[3]
GHS labelling:[3]
Pictograms
Signal word	Warning
Hazard statements	H302, H312
Precautionary statements	P280
NFPA 704 (fire diamond)	[4] 2 0 0
Safety data sheet (SDS)	Ambeed Inc. Strontium Oxalate SDS
Related compounds
Other anions	Strontium acetate Strontium carbonate
Other cations	Beryllium oxalate Magnesium oxalate Potassium oxalate Calcium oxalate Barium oxalate Praseodymium oxalate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Use in pyrotechnics

With the addition of heat, strontium oxalate will decompose based on the following reaction:^[1]

SrC₂O₄ → SrO + CO₂ + CO

Strontium oxalate is a useful red color emitter for use in pyrotechnics. It decomposes into strontium oxide, a good scarlet red emitter with two strong peaks at 595 and 597 nm. The oxide reacts with moisture in the atmosphere to form the hydroxide, so its three strong peaks of 682 nm, 671 nm, and 606 nm are also relevant.^[6]

Decomposition produces carbon monoxide (CO), which can reduce magnesium oxide (a broad spectrum emitter which can wash out colors) to magnesium gas, resulting in a more transparent flame. This makes it a better emitter than other common strontium compounds in the presence of magnesium:

MgO(s) + CO → Mg(g) + CO₂

When magnesium is not present, there is no benefit from the production of CO gas and strontium carbonate is usually preferable.^[1]

Chlorine donors or chlorinated oxidizers result in a shift towards formation of strontium chloride which produces a slightly different, deeper red spectrum, having its three strongest peaks at 674 nm, 661 nm, and 636 nm.^[6]