Overview

Silver(I) sulfide (SILL-ver one SUL-fide) is a grayish-black heavy powder. Most people are familiar with the compound as tarnish, the black coating that covers silver tableware and jewelry when they are exposed to the air.

How It Is Made

Silver(I) sulfide occurs naturally as the minerals acanthite and argentitde, from which they can be extracted by grinding, crushing, and washing the mineral ore. The compound can also be prepared synthetically by passing hydrogen sulfide (H₂S) gas through an aqueous solution of silver nitrate.

H₂S + 2AgNO₃ → Ag₂S + 2HNO₃

Key Facts

Other Names:

Argentous sulfide

Formula:

Ag₂S

Elements:

Silver, sulfur

Compound Type:

Binary salt (inorganic)

State:

Solid

Molecular Weight:

247.80 g/mol

Melting Point:

925°C (1520°F)

Boiling Point:

Not applicable; decomposes

Solubility:

Insoluble in water; soluble in nitric acid, sodium cyanide (NaCN), and potassium cyanide (KCN)

The silver(I) sulfide...