Lanthanum chloride anhydrous

Preparation

Lanthanum chloride anhydrous is formed by dissolving the oxide, hydroxide or carbonate in hydrochloric acid, followed by crystallization. The anhydrous chloride is obtained by heating oxide, hydroxide, or carbonate in an atmosphere of dry hydrogen chloride. La2(CO3)3 + 6HCl → 2LnCl3 + 3CO2 + 3H2O Another method involves heating lanthanum oxide with excess ammonium chloride at 300°C.

Reactions

When heated in the presence of water vapor, lanthanum oxochloride is formed: LaCl3 + H2O→LaOCl + 2HCl Heating with glass at elevated temperatures also forms oxochloride: LaCl3 + SiO2→2LaOCl + SiCl4 Lanthanum chloride reacts with hydrogen sulfide when heated at 1100°C, forming lanthanum sulfide: 2LaCl3 + 3H2S→La2S3 + 3H2S Reactions with ammonia and phosphine at elevated temperatures yield lanthanum nitride and phosphide, respectively: LaCl3 + PH3→LaP + 3HCl Lanthanum chloride is reduced to lanthanum metal when heated with an alkali or alkaline earth metal at temperatures above 1000°C: LaCl3 + 3Li→La + 3LiCl

Air & Water Reactions

Deliquescent. Water soluble.

Reactivity Profile

Aqueous solutions of LANTHANUM CHLORIDE contain moderate concentrations of hydrogen ions and react as acids to neutralize bases. Does not usually react as either oxidizing agents or reducing agents but such behavior is not impossible. May catalyze organic reactions.

Health Hazard

TOXIC; inhalation, ingestion or skin contact with material may cause severe injury or death. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.

Fire Hazard

Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated.

Physical Properties

The anhydrous chloride is a white hexagonal crystal; hygroscopic; density 3.84 g/cm3; melts at 850°C; soluble in water. The heptahydrate is a white triclinic crystal; decomposes at 91°C; soluble in water and ethanol.

General Description

Lanthanum(III) chloride is white crystalline solid. Gives an amber aqueous solution that can cause destruction or irreversible alterations in human skin tissue at the site of contact. Has a severe corrosion rate on steel.