Properties of Silver Nitrate or Lunar Caustic

Physical Properties Properties of Silver nitrate (AgNO3)

Physical Properties

  1. It is soluble in water.
  2. Its aqueous solution may decompose on exposure to light.


Chemical Properties

  • Action of Heat

On heating AgNO3 decomposes in two stages

2AgNO3 –723 K→ 2AgNO2 + O2  (Silver nitrite)

AgNO2 — 980 K→ Ag + NO2

  • With NaCl

AgNO3 gives white precipitate of AgCl with soluble ionic chlorides.

AgNO3 + NaCl → AgCl↓ + NaNO3

  • Silver nitrate is strongly caustic and oxidizing in nature.
  • With KBr & KI

AgNO3 gives pale yellow precipitate of AgBr with bromides and yellow AgI with iodides.

AgNO3 + KBr → AgBr + KNO3 (Yellow ppt)

AgNO3 + KI → AgI + KNO3 (Yellow ppt)

  • Action with organic compounds

Ammoniacal silver nitrate (Tollen’s reagent) is reduced to silver mirror by compounds like formic acid, formaldehyde or glucose:

2AgNO3 + 2NH4OH → Ag2O + 2NH4NO3 + H2O

Ag2O + HCOOH → 2Ag↓ + H2O + CO2