How To: Do the Leidenfrost Effect w/ methyl alcohol & a penny

This how-to video is about demonstrating the Leidenfrost effect with methyl alcohol and a penny.

To demonstrate the Leidenfrost effect the following items are required:

1)Methyl alcohol

2)Penny

3)Heat resistant dish

4)Burner and a holder

Understanding the Leidenfrost effect is important before performing the experiment. In this effect, the methyl alcohol will boil twice without catching fire, from the time when the hot penny is placed in the dish containing methyl alcohol. First, when the hot penny is put in the dish containing methyl alcohol, it will start boiling the methyl alcohol forming a vapor barrier between the methyl alcohol and the penny, this vapor barrier prevents the alcohol from catching on fire.

Secondly, as the penny cools down slowly the vapor barrier collapses and will start boiling again.

To perform this Leidenfrost effect, first heat the penny by introducing it into the flame from a burner, use the holder while heating the penny. Then place the penny in a heat resistant dish filled with methyl alcohol. As soon as the penny is placed in the dish containing alcohol, we can see the vapor barrier formed just above the penny, and after few seconds the vapor barrier will collapse resulting in second boiling as the penny cools down.

While practicing this effect, make sure that you don't heat the penny to very high temperature.

By watching this video, students can really understand Leidenfrost effect.