Introduction

The extraction of pure sodium chloride (NaCl) from a mixture involving sodium chloride, ammonium chloride (NH4Cl), and soil can be a complex but manageable process. This article will guide you through the steps to purify NaCl from such a mixture. Understanding the principles of each separation technique will ensure a successful final product.

Objective

The goal is to separate pure sodium chloride from a mixture containing sodium chloride, ammonium chloride, and soil. The desired end product is sodium chloride that is virtually free of other contaminants like ammonium chloride and any impurities from the soil.

Methods of Extraction

1. Removal of Soil

The first step involves removing the soil. Soil is usually the most insoluble contaminant and can be eliminated by filtration. Follow these steps:

Filteration: Pour the mixture of sodium chloride, ammonium chloride, and soil through a filter paper to remove the soil particles. This will leave a clear solution containing sodium chloride and ammonium chloride.

2. Separation of Ammonium Chloride

Ammountium chloride can be separated from the remaining solution using sublimation. Ammonium chloride sublimes (disappears into the atmosphere) when heated under certain conditions.

Sublimation: Heat the solution gently until the ammonium chloride has sublimated. This process should be conducted in a fume hood due to the release of toxic gases. Collect the sublimed ammonium chloride in a clean container.

3. Purification of Sodium Chloride

The final step is to purify the sodium chloride. This involves removing any remaining water and any other impurities. Follow these steps:

Boiling and Evaporation: Boil the filtrate under reduced pressure to drive off any remaining water and gaseous impurities. The water will evaporate, leaving behind a moist solid. This solid should be carefully dried to a pure form of sodium chloride. Avoiding Contamination: To check for the presence of other compounds, perform a chloride test using a silver nitrate solution. If the vapor or distillate contains chloride ions, it will form a white precipitate with silver nitrate. This step will help confirm that the process is complete.

Caveats and Challenges

It should be noted that the soil in the mixture may dissolve in water, making it challenging to completely separate all soil-based impurities. Therefore, the sodium chloride obtained after purification may still contain some low-level impurities.

Conclusion

By following the detailed steps outlined above, you can successfully extract pure sodium chloride from a mixture that includes sodium chloride, ammonium chloride, and soil. This process combines the use of filtration, sublimation, and evaporation to achieve a high degree of purity in the final product.