What is Nondistillable? Definition, Examples, and Reasons

Nondistillable refers to a substance that cannot be separated from a mixture or solution through distillation. Distillation is a process of separating components of a mixture based on their differences in boiling points, where the component with the lower boiling point vaporizes and is collected separately. However, some substances have similar boiling points or are not soluble in the solvent used for distillation, making it impossible to separate them from the mixture. These substances are considered nondistillable.

Examples of nondistillable substances include:

1. Mixtures with multiple components that have similar boiling points: For example, a mixture of ethanol and water has a similar boiling point range, making it difficult to separate the two components through distillation.
2. Substances that are not soluble in the solvent used for distillation: For example, a substance that is insoluble in water cannot be separated from a mixture of water through distillation.
3. Substances with complex molecular structures: Some substances have complex molecular structures that make them difficult to separate through distillation. For example, proteins and other biomolecules are often nondistillable due to their complex structure and high boiling point.
4. Substances with strong intermolecular forces: Substances with strong intermolecular forces, such as hydrogen bonding or van der Waals forces, can be difficult to separate through distillation because the forces hold the molecules together and prevent them from vaporizing.

In summary, nondistillable substances are those that cannot be separated from a mixture or solution through distillation due to similar boiling points, insolubility in the solvent, complex molecular structure, or strong intermolecular forces.