Ignition Test for High Degrees of Unsaturation

Standards
Benzophenone, cyclohexane, and hexanes.

Procedure
Heat a small sample on a spatula. First, hold the sample near the side of a bunsen burner to see if it melts normally and then burns. Heat it in the flame. Aromatic compounds often burn with a smoky flame.

Positive Test
A sooty yellow flame is an indication of an aromatic ring or other centers of unsaturation