What is the process of sublimation in separation?

Sublimation in separation is a process where a solid changes directly into a gas, without becoming a liquid first.

Sublimation is a technique used in the field of chemistry to separate mixtures. It is based on the principle that some substances have the ability to change their state directly from solid to gas without passing through the liquid state. This process is called sublimation. The substance that undergoes sublimation is called a sublimate.

In the process of separation, the mixture is heated gently. The substance that sublimates transforms into a gas, leaving behind the other substances. The gas is then cooled down or condensed back into a solid form in a separate container. This method is particularly useful when the other components of the mixture are either liquid or solid at the temperature at which the sublimate substance turns into a gas.

A common example of a substance that undergoes sublimation is dry ice, or solid carbon dioxide. When heated, it changes directly into carbon dioxide gas without becoming a liquid. Another example is iodine, which sublimates when heated and forms a purple vapour.

In the context of separation techniques, sublimation is a very effective method as it allows for the separation of substances without any chemical reaction taking place. It is also a relatively simple process that does not require complex equipment. However, it is important to note that this method can only be used for substances that have the property of sublimation.

In summary, sublimation is a useful technique in chemistry for the separation of mixtures. It relies on the unique property of some substances to change their state directly from solid to gas, bypassing the liquid state. This allows for a clean and efficient separation of components in a mixture.