Experimental Procedure for Separating a Mixture of Ammonium Chloride, Sodium Chloride, and Silicon Dioxide

Initial Preparation and Sublimation

The process began by measuring the initial masses of the crucible, receiving beaker, filter paper, and the 2.48g solid mixture sample. The ammonium chloride was removed via thermal sublimation in a fume hood, heating the mixture until all fumes and condensation ceased, indicating complete removal of the component.

Dissolution and Filtration

After determining the mass lost to sublimation, the remaining solid residue (sodium chloride and silicon dioxide) was mixed with 7mL of distilled water to dissolve the salt. This mixture was filtered through pre-weighed filter paper, with the remaining silicon dioxide rinsed repeatedly with additional distilled water to ensure complete transfer of the dissolved sodium chloride into the receiving beaker.

Drying and Final Weighing

The silicon dioxide trapped on the filter paper was dried at 105 degrees Celsius for 30 minutes, resulting in a final mass of 2.56g. Simultaneously, the sodium chloride solution in the beaker was heated until all water evaporated, leaving behind the salt, with the final beaker mass recorded at 169.42g.