How Is Silver Selenite Formed?

Silver selenite, also known as silver(I) selenite or Ag2SeO3, is an ionic compound consisting of silver cations (Ag+) and selenite anions (SeO32-). It is formed through a chemical reaction between silver nitrate (AgNO3) and sodium selenite (Na2SeO3):

AgNO3 + Na2SeO3 → Ag2SeO3 + 2NaNO3

In this reaction, the silver cations from the silver nitrate combine with the selenite anions from the sodium selenite to form solid silver selenite. The sodium and nitrate ions remaining in the solution combine to form soluble sodium nitrate.

Silver selenite can also be prepared by reacting silver carbonate (Ag2CO3) with selenium dioxide (SeO2):

Ag2CO3 + SeO2 → Ag2SeO3 + CO2

In this reaction, the silver carbonate reacts with the selenium dioxide to form solid silver selenite and carbon dioxide gas.

Once formed, silver selenite is a white crystalline solid that is insoluble in water but soluble in acids. It has a high melting point and is often used in the production of silver selenide, which is a semiconductor material used in optoelectronics.