Destructive distillation of coal is used to produce coal tar and coke. This is an example of which technique?

• A. Fermentation
• B. Crystallization
• C. Distillation
• D. Precipitation

Answer: (C)

Distillation is a method that separates components based on how easily they vaporize. In destructive distillation of coal, heat is applied to decompose the coal in the absence of air. The volatile fragments vaporize and are then condensed into coal tar, while the solid residue remains as coke. This illustrates distillation because you're obtaining different products by condensing the vapors from heating, even though the feed is also chemically breaking down. It’s not fermentation (biological), crystallization (crystal formation from a solution), or precipitation (solid forming from a solution).