Copper(II) nitrate hydrate (Cu(NO3)2•xH2O)-Crystalline

Characteristic

Copper(II) nitrate, Cu(NO₃)₂, is an inorganic compound that forms a blue crystalline solid. Anhydrous copper nitrate forms deep blue-green crystals and sublimes in a vacuum at 150-200 °C. Copper nitrate also occurs as five different hydrates, the most common ones being the trihydrate and hexahydrate. These materials are more commonly encountered in commerce than in the laboratory.

Chemical formula:Cu(NO₃)₂•xH₂O

Molar mass: 187.5558 g/mol (anhydrous);241.60 g/mol (trihydrate);232.591 g/mol (hemipentahydrate)

Appearance:blue crystals;hygroscopic

Density:3.05 g/cm³ (anhydrous);2.32 g/cm³ (trihydrate);2.07 g/cm3 (hexahydrate)

Melting point:256 °C (493 °F; 529 K) (anhydrous, decomposes);114.5 °C (trihydrate);26.4 °C (hexahydrate, decomposes)

Boiling point:170 °C (338 °F; 443 K) (trihydrate, decomposes)

Solubility in water:trihydrate:381 g/100 mL (40 °C);666 g/100 mL (80 °C);

                    hexahydrate:243.7 g/100 mL (80 °C)

Solubility:hydrates very soluble in ethanol, ammonia, water; insoluble in ethyl acetate

Magnetic susceptibility (χ):+1570.0·10−6 cm³/mol (~3H2O)

Crystal structure:orthorhombic (anhydrous);rhombohedral (hydrates)

Application

It serves as a catalyst for oxidative coupling of 2,6-dimethylphenol, resulting in an important engineering polymer material. Also used in textiles and polishing agents for other metals. It is a precursor for copper oxide, which finds use as a catalyst for many organic transformations. Menke conditions employ copper nitrate for aromatic nitrations. Claycop reagent, the hydrated copper nitrate deposited on clay, finds use in many organic reactions, for example, oxidation of dithioacetals to carbonyls and thiols to disulfides.