Silver Nitrate (AgNO3)
Silver Nitrate (AgNO3)
Silver Nitrate is commonly known as Lunar caustic. Preparation AgNO3 is prepared by dissolving silver metal in dil HNO3. The silver nitrate solution of crystallization gives colorless crystal of AgNO3. 3Ag + 4HNO3 ? 3AgNO3 + NO + 2H2O. Properties It is colorless crystalline solid soluable in water. It is highly sensitive to light and when kept in contact with skins it leaves a permanent dark stain. Action of heat. When silver nitrate is heated first it decompose forming silver nitrite which on further heating decompose giving silver metal. 2AgNO3 ? 2AgNO2 + O2 AgNO2 ? Ag + NO2 Precipitation reaction AgNO3 gives precipitate with halide ion (Cl, Br & I ) and from color of precipitate the halide ion can be identified. Cl + AgNO2 ? AgC + NO3 Curdy white Br + AgNO2 ? AgBr + NO3 Pale yellow I + AgNO2 ? AgI + NO3 Yellow ppt Ammonical Silver Nitrate [Tollen’s reagent] is used to detect reducing groups in organic compounds like aldetyde. The reducing agent reduces tollen’s reagent to metallic silver which deposits in test-tube forming silver mirror. Ag2O + HCHO ? 2Ag + HCOOH Toller’s reagent Uses i. it is used in makingsilver halides used in photography. ii. It is used in making inks and hair dye’s. iii. It is used in making silver mirror. iv. It is used in lab as analytical reagent.