Silver nitrate
White silver nitrate, AgNO3, is a versatile precursor to many other silver compounds, especially the halides, and is much less sensitive to light. It was once called "lunar caustic" because silver was called "luna" by the ancient alchemists, who believed that silver was associated with the moon. It is often used for gravimetric analysis, exploiting the insolubility of the heavier silver halides which it is a common precursor to. Silver nitrate is used in many ways in organic synthesis, e.g. for deprotection and oxidations. Ag+ binds alkenes reversibly, and silver nitrate has been used to separate mixtures of alkenes by selective absorption. The resulting adduct can be decomposed with ammonia to release the free alkene.