Silver nitrate

Silver nitrate is an inorganic compound with the chemical formula AgNO₃. This compound is a versatile precursor to many other silver compounds, such as those used in photography. It has antiseptic properties and was historically used to prevent gonorrhea and ophthalmia neonatorum, the latter being a condition in newborns caused by infection with Neisseria gonorrhoeae. Silver nitrate is also used in analytical chemistry, for precipitation reactions, and in silver plating.

Properties

Silver nitrate is colorless, crystalline, and soluble in water. Its solutions are used in mirror production because they readily reduce to metallic silver upon exposure to organic material, such as glucose, in the presence of a base. This property also underlies its use in photography, where silver nitrate solutions are applied to films and paper.

Medical Uses

Historically, silver nitrate was used in a 1% solution to prevent ophthalmia neonatorum, a practice that has been largely replaced by antibiotic treatments. Its antiseptic and astringent properties make it useful in the treatment of minor wounds, ulcers, and skin infections. Silver nitrate sticks, also known as lunar caustic sticks, are applied topically to remove warts, granulation tissue, and for cauterization of minor wounds.

Safety

Silver nitrate is corrosive to the skin and eyes, and can cause argyria, a condition characterized by the bluish-gray discoloration of the skin, eyes, and mucous membranes. Safety measures include wearing gloves and eye protection when handling this chemical.

Chemical Reactions

Silver nitrate reacts with hydrochloric acid to form silver chloride, a white precipitate, according to the equation: \[ \text{AgNO}_3 + \text{HCl} \rightarrow \text{AgCl} + \text{HNO}_3 \] This reaction is used in the qualitative analysis of chloride ions.

Applications in Chemistry

In addition to its use in photography and medicine, silver nitrate is employed in electroplating, in the synthesis of other silver compounds, and as a standard in titration procedures in analytical chemistry.

Environmental Impact

Silver compounds, including silver nitrate, can be toxic to aquatic life. They accumulate in the environment and can cause long-term damage to ecosystems. Proper disposal methods are essential to minimize environmental impact.

See Also

• Silver
• Nitrate
• Analytical chemistry
• Antiseptic
• Cauterization