Physical properties
Anhydrous copper sulfate :
Appearance and properties: Anhydrous copper sulfate is an off-white powder, copper sulfate pentahydrate that easily absorbs water and turns blue-green.
Melting point: 560°C.
Density: 3.606 g/cm 3 (25ºC)
Vapor pressure: 7.3mm Hg (25ºC)
Solubility: soluble in water and methanol. Insoluble in ethanol.
Copper sulfate pentahydrate :
The physical and chemical properties of copper sulfate pentahydrate are transparent dark blue crystals or powders. The solubility in water at 0°C is 316 g/L. It is insoluble in ethanol and almost insoluble in most other organic solvents. It is gem green in glycerin, and slowly weathered in the air. It loses two molecules of crystal water (30°C) when heated, and becomes a white hydrate (CuS0 4 ·H 2 0) when it loses water at 110°C . It is yellow or green when it contains impurities and is odorless. This product is very corrosive to iron. Copper sulfate is both a fertilizer and a commonly used fungicide. Bordeaux liquid , copper soap liquid, and copper ammonium preparations are prepared with copper sulfate, quicklime, soap, and ammonium bicarbonate .
Chemical nature
1. Hydrates can easily absorb water vapor in the air and become hydrates. Hydrate loses crystal water after heating, and loses two crystal waters when heated to 102°C; loses three crystal waters at 113°C; loses all crystal water at 258°C; when the heating temperature reaches 653°C, it begins to decompose to produce CuO and SO 3 , The decomposition is over at 720°C.
The changes in the formation of crystal water are as follows:
The changes that occur at different temperatures are as follows:
2. It has a substitution reaction with elemental substances whose activity sequence is before copper, such as iron and zinc, but cannot be replaced with overly active metals (such as sodium, potassium, etc.).
3. React with alkali
It reacts with ammonia to produce copper hydroxide in a small amount, and produces a complex tetraammine copper sulfate in an excessive amount .
Phenomenon: Add a small amount of ammonia to the copper sulfate solution , and a blue precipitate is formed; continue to add ammonia, the precipitate is dissolved, and a dark blue solution is formed. When ethanol was added, a dark blue precipitate precipitated out.
Account not verified