How to make 10 grams of copper stearate out of copper sulfate
To make copper stearate from copper sulfate, you'll need stearic acid and a source of copper ions, which can be derived from copper sulfate. The reaction involves the precipitation of copper stearate from the reaction of stearic acid with copper sulfate.
Here’s a step-by-step process to prepare 10 grams of copper stearate:
### Materials Needed:
1. **Copper Sulfate (CuSO₄)**
2. **Stearic Acid (C₁₈H₃₆O₂)**
3. **Distilled Water**
4. **Beakers or containers for mixing**
5. **pH paper or a pH meter (optional, for checking pH)**
6. **Heating source (Bunsen burner, hot plate, etc.)**
7. **Stirring rod**
8. **Filter paper and funnel (for filtration)**
9. **Balance (for measuring)**
10. **Glassware (such as flasks, beakers)**
### Calculations:
1. Determine the molar mass of copper stearate:
- The molar mass of copper stearate (Cu(C₁₈H₃₆O₂)₂) is approximately 575. These calculations lead to:
- Copper (Cu): 63.55 g/mol × 1 = 63.55 g
- Stearate (C₁₈H₃₆O₂): 284.47 g/mol × 2 = 568.94 g
- Total ≈ 632.49 g/mol
2. Amount (in moles) needed for 10 grams of copper stearate:
\[
\text{n} = \frac{10 \text{ g}}{632.49 \text{ g/mol}} \approx 0.0158 \text{ moles}
\]
### Procedure:
1. **Prepare Copper Sulfate Solution**:
- Weigh out the appropriate amount of copper sulfate to provide the necessary copper ions. Since one mole of copper stearate requires one mole of copper, 0.0158 moles of CuSO₄ is required:
\[
\text{Mass of CuSO₄} = 0.0158 \text{ moles} \times 160.25 \text{ g/mol} \approx 2.53 \text{ g}
\]
- Dissolve 2.53 g of copper sulfate in a small amount of distilled water (e.g., 50 mL) in a beaker.
2. **Prepare Stearic Acid Solution**:
- Measure out approximately 11.3 g of stearic acid (2 moles since two stearate groups are needed).
- Heat the stearic acid gently until it is fully melted.
3. **Combine Reactants**:
- Slowly add the copper sulfate solution into the melted stearic acid while stirring continuously. You should observe the formation of a precipitate (copper stearate).
4. **Filtration**:
- Once the reaction is complete, let the mixture cool down. Use a filter paper and funnel to filter the solution, collecting the precipitate of copper stearate.
5. **Wash and Dry**:
- Wash the precipitate with distilled water several times to remove any unreacted starting materials and impurities.
- Allow the copper stearate to dry completely.
6. **Final Product**:
- After drying, you should have approximately 10 grams of copper stearate. Weigh the final product to ensure you have achieved the desired quantity.
### Safety Precautions:
- Wear gloves and safety goggles while handling chemicals.
- Perform the reaction in a well-ventilated area or under a fume hood.
This method will yield copper stearate, which is used in various applications, including as a surfactant, in lubricants, and in the formulation of some types of coatings.