Strontium nitrate

Description

Strontium nitrate has the molecular formula of Sr(NO3)2 and the molecular weight of 211.6327 g/mol. Strontium nitrate is prepared by treating strontium carbonate with nitric acid. The solution is evaporated and crystallized:
SrCO3 +HNO3 ? Sr(NO3)2 + CO2 +H2O
Crystallization yields the tetrahydrate, Sr(NO3)2· 4H2O, which, on heating, melts at 31.3 °C in its own waters of hydration and then decomposes >100 °C to form the anhydrous nitrate. The anhydrate melts at 570 °C (It begins to decompose as low as 545 °C), is soluble in water (70.3 gm/100 ml at 20 °C) and is very slightly soluble in ethanol. These colorless crystals, or white powder, have a density of 2.986 g/cm³ and its CAS number is 10042-76-9. It is very soluble in water, as shown in Table 4.11 on the following page. Strontium nitrate apparently forms only the tetrahydrate when a solution is evaporated below 80°C. Otherwise it decomposes at higher solution temperatures to Sr(OH)2 and nitrogen oxides. The nitric acid concentration makes little difference in the hydrate produced, in contrast to other alkaline earths like Ca and Mg.

Chemical properties

Colorless cubic crystals or white powder or granules; density 2.986 g/cm3; melts at 570°C; very soluble in water, 80 g/100 mL at 18°C; very slightly soluble in ethanol.
The tetrahydrate constitutes colorless monoclinic crystals; density 2.20 g/cm3; loses all water of crystallization at 100°C; converts to strontium oxide, SrO at 1,100°C; very soluble in water, 60.4g/100 mL at 0°C, 206 g/100 mL at 100°C; soluble in liquid ammonia; very slightly soluble in ethanol and acetone.

Chemical properties

Strontium nitrate is a white crystalline solid

Physical properties

Colorless cubic crystals or white powder or granules; density 2.986 g/cm³; melts at 570°C; very soluble in water, 80 g/100 mL at 18°C; very slightly soluble in ethanol.
The tetrahydrate constitutes colorless monoclinic crystals; density 2.20 g/cm³; loses all water of crystallization at 100°C; converts to strontium oxide, SrO at 1,100°C; very soluble in water, 60.4g/100 mL at 0°C, 206 g/100 mL at 100°C; soluble in liquid ammonia; very slightly soluble in ethanol and acetone.

The Uses of Strontium nitrate

Strontium nitrate is used in pyrotechnics, for producing marine and railroad signals, and in matches.

The Uses of Strontium nitrate

Used in preparation of strontium standard solutions

The Uses of Strontium nitrate

In pyrotechnics (red fire), signal lights, marine signals, railroad flares, matches.

The Uses of Strontium nitrate

Strontium nitrate [Sr(NO3)2], because of the bright red flame it produces when burned, is used in fireworks, matches, marine signals, and so forth.

The Uses of Strontium nitrate

Industrial uses of strontium nitrate are rather limited and have rather limited commercial value because the corresponding calcium and barium compounds serve the same purpose yet are cheaper. A few, however, have found application in industry and elsewhere. Strontium nitrate, Sr(NO3)2, and strontium chlorate,Sr(ClO3)2, are extremely volatile and impart a brilliant crimson color to flames; they are thus used in fireworks and similar displays.
Recent clinical studies demonstrate that when strontium nitrate is applied to the facial skin, it significantly reduces skincare-induced burning, stinging and facial redness. These findings are very important to Rosacea sufferers, who report facial burning and flushing to topical skincare products and environmental insults such as wind, sun, heat and cold. This is the first compound that selectively blocks the irritationproducing nerve endings (type C nociceptors) that become activated when itching, burning and stinging occur from any cause. Glycolic acid removes the upper layer of old and dead skin cells, while encouraging the growth of younger, smoother and evenly pigmented looking skin. Strontium nitrate is a substance capable of inhibiting tingling sensations and irritations associated with peels containing glycolic acid. It reduces irritations, inflammations, and redness caused by glycolic acid peels.

Preparation

Strontium nitrate is prepared by treating strontium carbonate with nitric acid. The solution is evaporated and crystallized:
SrCO3 + HNO3 → Sr(NO3)2 + CO2 + H2O
Crystallization yields the tetrahydrate, Sr(NO3)2•4H2O, which on heating dehydrates to form the anhydrous nitrate.

brand name

Strotope (Bristol-Myers Squibb).

General Description

A white crystalline solid. Noncombustible but accelerates burning of combustible materials. May explode if large quantities are involved in a fire or the combustible material is finely divided. May explode under prolonged exposure to heat or fire. Toxic oxides of nitrogen are produced in fires. Used in pyrotechnics, in medicine, and to make other chemicals.

Air & Water Reactions

Soluble in water.

Reactivity Profile

Mixtures of metal/nonmetal nitrates with alkyl esters may explode, owing to the formation of alkyl nitrates; mixtures a nitrate with phosphorus, tin (II) chloride, or other reducing agents may react explosively [Bretherick 1979 p. 108-109]. Special Hazards of Combustion Products: Yields toxic gaseous oxides of nitrogen when involved in fire.

Health Hazard

Dust is irritating to skin, eyes, and respiratory system.

Flammability and Explosibility

Non flammable

Safety Profile

Moderately toxic by ingestion and intraperitoneal routes. A powerful oxidizer. When heated to decomposition it emits toxic fumes of NOx.See also NITRATES and STRONTIUM COMPOUNDS.

Potential Exposure

Strontium nitrate is used in matches, pyrotechnics, marine signals; and railroad flares.

Shipping

UN1507 Strontium nitrate, Hazard Class: 5.1; Labels: 5.1-Oxidizer.

Purification Methods

Crystallise it from hot water (0.5mL/g) by cooling to 0o.

Incompatibilities

A strong oxidizer. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Violent reaction with reducing agents; combustibles, organics, or other readily oxidizable materials. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides.