Copper(II) nitrate

Cu(NO₃)₂     Copper(II) Nitrate

Chemical Formula: Cu(NO₃)₂ (anhydrous) or Cu(NO₃)₂·xH₂O (hydrate, common x=3, 6)  

1. Basic Properties

- Appearance:  

  - Anhydrous Cu(NO₃)₂: White or light green powder (hygroscopic).  

  - Trihydrate (Cu(NO₃)₂·3H₂O)**: Blue crystals (most common).  

  - Hexahydrate (Cu(NO₃)₂·6H₂O)**: Dark blue crystals (stable at low temperatures).  

- Solubility: Easily soluble in water, ethanol, and liquid ammonia; aqueous solution is acidic.  

- Hygroscopicity: Anhydrous Cu(NO₃)₂ is highly hygroscopic and must be stored sealed.  

- Thermal Stability: Decomposes upon heating, forming copper oxide (CuO), nitrogen dioxide (NO₂), and oxygen (O₂).  

3. Main Uses 

- Catalyst: Used in organic synthesis (e.g., nitration reactions).  

- Electroplating: Electrolyte component for copper plating.  

- Fireworks/Pyrotechnics: Produces blue-green flames when burned (copper ion flame test).  

- Laboratory Uses:  

  - Preparation of other copper compounds (e.g., copper oxide, copper hydroxide).  

  - Oxidizing agent or analytical reagent.  

- Agriculture: Occasionally used as a fungicide (though less common).  

4. Safety Precautions

- Toxicity:  

  - Harmful if ingested or inhaled; irritates the respiratory and digestive tracts.  

  - Long-term exposure may damage the liver and kidneys.  

- Corrosiveness: Aqueous solution is acidic; rinse immediately upon contact with skin or eyes.  

- Environmental Hazard: Toxic to aquatic life; waste liquids must be properly disposed of.  

- Storage: Store sealed, away from light and moisture (hygroscopic).