When the mixture to be distilled has a very high boiling point and the product material is heat sensitive, the separation technique to be used is __________ distillation.

ANS:B - steam

Certainly! Steam distillation is a special type of distillation technique used to separate heat-sensitive compounds from less volatile materials. It is particularly useful for extracting essential oils, flavors, and fragrances from natural sources like plants and herbs. Here's how it works:

1. Boiling Water: Steam distillation involves boiling water in a flask or boiler. As the water boils, it produces steam.
2. Passing Steam Through Plant Material: The steam generated from the boiling water is passed through the plant material containing the compounds to be extracted. The heat from the steam causes the volatile compounds in the plant material to vaporize.
3. Vaporization of Compounds: The vaporized compounds from the plant material mix with the steam, forming a mixture of steam and volatile compounds.
4. Condensation: The steam and volatile compound mixture is then passed through a condenser, where it is cooled and condensed back into a liquid. The condensed liquid contains the volatile compounds dissolved in it.
5. Separation: Since the volatile compounds are insoluble in water, they separate from the aqueous distillate and float on top as an essential oil layer.
6. Collection: The essential oil layer is then collected separately from the aqueous layer.

Steam distillation is preferred for heat-sensitive compounds because it operates at lower temperatures compared to traditional distillation methods. By using steam, the extraction process can occur at temperatures well below the boiling points of the compounds being extracted, reducing the risk of thermal degradation or decomposition. Additionally, steam can penetrate plant material more effectively, allowing for better extraction of volatile compounds. Overall, steam distillation is a gentle and efficient method for extracting essential oils and other heat-sensitive compounds from natural sources.