You can separate a mixture of iodine, salt, and sand using a combination of sublimation, dissolution, and evaporation techniques.
Here's a detailed breakdown of the process:
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Sublimation of Iodine:
- Iodine readily undergoes sublimation, which means it transitions directly from a solid to a gas when heated, without passing through a liquid phase. Gently heat the mixture.
- Cover the container with a cool surface (like an inverted watch glass). The gaseous iodine will re-solidify on this cool surface, separating it from the salt and sand. This process collects relatively pure iodine crystals.
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Dissolving the Salt:
- After removing the iodine, you're left with a mixture of salt and sand. Salt (sodium chloride) is highly soluble in water, while sand (silicon dioxide) is not.
- Add water to the remaining mixture and stir thoroughly. The salt will dissolve, forming a salt solution, while the sand will remain undissolved as a solid.
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Separating the Sand:
- Use filtration to separate the sand from the salt solution. Pour the mixture through a filter paper placed in a funnel. The salt solution will pass through the filter paper, while the sand particles will be trapped on the filter paper as a residue.
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Recovering the Salt:
- Evaporate the water from the salt solution to recover the salt. This can be done by gently heating the solution, allowing the water to evaporate, leaving behind solid salt crystals. Alternatively, a slow evaporation process can be used to obtain larger, more well-formed salt crystals.
In summary, the separation process leverages the unique properties of each component: iodine's ability to sublime, salt's solubility in water, and sand's insolubility in water.
