Steam Distillation Ch.5

What is steam distillation?

A technique where volatile compounds are co-distilled with water at temperatures below their normal boiling points.

Why does steam distillation allow boiling at lower temperatures?

The vapor pressure of the mixture equals atmospheric pressure at a lower temperature when both water + volatile compound contribute to vapor pressure.

What types of compounds are separated by steam distillation?

Volatile compounds that are immiscible with water, often found in essential oils and plant materials.

Why is steam distillation useful for essential oils?

It prevents decomposition of heat-sensitive compounds by distilling them at reduced temperatures.

What is the main purpose of this experiment?

1. Perform a microscale steam distillation of lemongrass oil

2. Isolate citral (mix of geranial + neral)

3. Perform simple extraction based on solubility

What compound is isolated from lemongrass during this lab?

Citral, a mixture of geranial and neral.

What happens when steam passes through the plant material?

Volatile compounds vaporize with the steam and are distilled over.

After distillation, how is the volatile compound separated from water?

Through extraction, based on differences in solubility.

What is the advantage of using steam vs. regular distillation?

Allows purification of compounds with high boiling points without overheating them.