Arsenic(III) chloride, also known as arsenous chloride or arsenic trichloride, is a chemical compound with the formula AsCl3. It is an important and toxic compound of arsenic and chlorine.

Here are some key points about arsenic(III) chloride:

1. Structure: Arsenic(III) chloride has a molecular structure where one arsenic (As) atom is bonded to three chlorine (Cl) atoms.
2. Preparation: Arsenic(III) chloride is typically prepared by the direct combination of arsenic and chlorine gas or by reacting arsenic trioxide (As2O3) with hydrochloric acid (HCl).
3. Physical Properties: Arsenic(III) chloride is a colorless to yellowish liquid at room temperature and pressure. It has a pungent and suffocating odor.
4. Hydrolysis: Arsenic(III) chloride is highly reactive with water and undergoes hydrolysis to produce arsenic acid (H3AsO4) and hydrogen chloride gas (HCl).
5. Uses: Arsenic(III) chloride is mainly used in the synthesis of organoarsenic compounds, which find applications in various industries, such as agriculture, electronics, and pharmaceuticals.
6. Toxicity: Arsenic(III) chloride is highly toxic and poses significant health hazards if ingested, inhaled, or comes into contact with skin or eyes. It is considered a highly dangerous substance.
7. Safety Considerations: Due to its toxicity and reactivity, arsenic(III) chloride should be handled with extreme caution. Proper safety protocols, including appropriate protective equipment and ventilation, should be observed when working with this compound.

Arsenic(III) chloride plays a crucial role in the synthesis of organoarsenic compounds, which have various applications in industry and research. However, its toxicity requires careful handling and containment to ensure the safety of those working with the compound. As with any highly toxic substance, strict safety measures should be followed to avoid unnecessary exposure and potential hazards.