Preparing copper sulphate solution involves reacting a copper source with sulphuric acid. Based on the provided information, there are two primary methods.
Method 1: Reaction with Metallic Copper
One way to prepare copper sulphate is by reacting metallic copper directly with sulphuric acid under specific conditions. As stated in the reference: "Copper sulphate is prepared by reacting metallic copper with hot concentrated sulphuric acid at high temperature conditions."
This method relies on the oxidizing power of hot, concentrated sulphuric acid to react with the relatively unreactive copper metal.
- Reactants: Metallic copper (Cu) and hot, concentrated sulphuric acid (H₂SO₄).
- Conditions: High temperature is essential for this reaction to occur effectively.
- Reaction: The reaction produces copper(II) sulphate, sulfur dioxide gas (SO₂), and water. The SO₂ gas is toxic and requires adequate ventilation.
- Equation (Simplified): Cu + 2H₂SO₄ (conc., hot) → CuSO₄ + SO₂ + 2H₂O
This method is typically used in industrial settings or under controlled laboratory conditions due to the hazardous nature of concentrated acid and sulfur dioxide gas.
Method 2: Reaction with Copper Oxide
A simpler and often safer alternative involves using copper(II) oxide instead of metallic copper. According to the reference: "Another method for preparing copper sulphate solution is by treating copper oxide with dilute sulphuric acid."
This method is a straightforward acid-base reaction:
- Reactants: Copper(II) oxide (CuO) and dilute sulphuric acid (H₂SO₄).
- Conditions: The reaction occurs readily at moderate temperatures, often simply by mixing. Heating gently can speed up the process.
- Reaction: Copper(II) oxide, a basic oxide, reacts with the acidic solution to form copper(II) sulphate and water. This reaction does not produce toxic gases.
- Equation: CuO + H₂SO₄ (dilute) → CuSO₄ + H₂O
This method is commonly used in educational settings and laboratories due to its simplicity, the use of less hazardous dilute acid, and the absence of toxic gaseous byproducts. Any undissolved copper oxide can be easily removed by filtration to obtain a clear blue copper sulphate solution.
Choosing the method depends on the available materials and the desired scale and safety level of the preparation.
