How to make 10 g of copper oxalate

To make copper oxalate (CuC₂O₄), you will need to react a soluble copper source with oxalic acid. Here are the steps to prepare approximately 10 grams of copper oxalate:

### Materials Needed

1. **Copper(II) sulfate pentahydrate (CuSO₄·5H₂O)** or any soluble copper salt
2. **Oxalic acid dihydrate (C₂H₂O₄·2H₂O)** or sodium oxalate
3. **Distilled water**
4. **Beakers and stirring rod**
5. **Filtration apparatus (e.g., filter paper and funnel)**
6. **Evaporating dish (optional)**

### Stoichiometry

To produce copper oxalate, the reaction can be represented as follows:

\[
\text{CuSO}_4 + \text{C}_2\text{H}_2\text{O}_4 \rightarrow \text{CuC}_2\text{O}_4 + \text{H}_2\text{SO}_4
\]

### Calculation of Required Reagents

1. **Molar Mass Calculation:**
   - Molar mass of CuC₂O₄ = 63.55 (Cu) + 2 × 12.01 (C) + 4 × 16 (O) = 63.55 + 24.02 + 64 = 151.57 g/mol.
   - To prepare 10 g of CuC₂O₄, you need:
     \[
     \text{Moles of CuC}_2\text{O}_4 = \frac{10 \text{ g}}{151.57 \text{ g/mol}} \approx 0.066 \text{ moles}
     \]

2. **Copper Source:**
   - From the stoichiometry of the reaction, 1 mole of CuSO₄ produces 1 mole of CuC₂O₄. Therefore, you need 0.066 moles of CuSO₄.
   - Molar mass of CuSO₄·5H₂O = 63.55 (Cu) + 32.07 (S) + 16 × 4 (O) + 5 × 18.02 (H₂O) = 249.68 g/mol.
   - Mass of CuSO₄·5H₂O needed = 0.066 moles × 249.68 g/mol ≈ 16.48 g.

3. **Oxalic Acid:**
   - Similarly, you need 0.066 moles of oxalic acid to react with CuSO₄. 
   - Molar mass of C₂H₂O₄·2H₂O = 90.03 g/mol.
   - Mass of oxalic acid needed = 0.066 moles × 90.03 g/mol ≈ 5.94 g.

### Procedure

1. **Dissolution:**
   - Dissolve approximately 16.5 g of copper(II) sulfate pentahydrate in about 50 mL of distilled water in a beaker.
   - In a separate container, dissolve approximately 5.9 g of oxalic acid dihydrate in about 50 mL of distilled water.

2. **Mixing:**
   - Slowly add the oxalic acid solution to the copper sulfate solution while stirring continuously.
   - A precipitate of copper oxalate should form almost immediately.

3. **Filtration:**
   - Allow the mixture to settle for a few minutes, then filter the mixture using a filter paper and funnel to collect the copper oxalate precipitate.

4. **Washing:**
   - Wash the precipitate with distilled water to remove any unreacted materials or impurities.

5. **Drying:**
   - Transfer the copper oxalate to an evaporating dish and place it in a warm, dry location to dry completely.

### Safety and Disposal

- Always wear appropriate personal protective equipment (gloves, goggles, lab coat) when handling chemicals.
- Dispose of any chemical waste according to local regulations.

### Final Note

The yield of copper oxalate may not be exactly 10 g due to incomplete reactions or losses during the procedure. Adjust the quantities accordingly if you need a precise amount. Always perform reactions in a fume hood or well-ventilated area, especially when dealing with acids.