Name the technique to separate camphor from salt.

The technique used to separate camphor from salt is known as sublimation. This method takes advantage of the physical properties of the substances involved, particularly their different states of matter and how they respond to heat.

Understanding Sublimation

Sublimation is a process where a solid transitions directly into a gas without passing through the liquid state. Camphor, a solid at room temperature, sublimates when heated, meaning it can turn into vapor and then condense back into a solid upon cooling. Salt, on the other hand, does not sublimate; it remains solid when heated.

Steps to Separate Camphor from Salt

• Preparation: Begin by mixing the camphor and salt together in a container.
• Heating: Gently heat the mixture. As the temperature rises, the camphor will start to sublime.
• Collection: Place an inverted lid or a cool surface above the heated mixture. The camphor vapor will rise, hit the cooler surface, and condense back into solid camphor.
• Separation: Once the camphor has condensed, it can be scraped off the cool surface, leaving the salt behind.

Why This Method Works

The effectiveness of sublimation in this separation process lies in the distinct physical properties of camphor and salt. While camphor has a relatively low boiling point and readily transitions to gas, salt remains stable and does not change state under the same conditions. This difference allows for a clean separation without the need for solvents or complex chemical reactions.

Real-World Applications

Sublimation is not only useful in the laboratory for separating substances like camphor and salt but also has broader applications. For instance, it is used in freeze-drying food, where moisture is removed by sublimating ice directly into vapor, preserving the food's structure and nutrients.

In summary, sublimation is a straightforward and effective technique for separating camphor from salt, leveraging the unique properties of each substance to achieve a clean separation. This method showcases the fascinating principles of physical chemistry in action.