Ammonium dichromate volcano

Ammonium dichromate decomposes to form nitrogen, water vapor, and chromium(III) oxide.

An alcohol-soaked fuse is placed upon a small mound of ammonium dichromate and ignited. The orange ammonium dichromate decomposes to form nitrogen, water vapor, and fluffy greenish-black chromium(III) oxide.

Equation:
(NH4)2Cr2O7 —> N2 + 4H2O + Cr2O3

Credits: 
  • Demonstration and Setup
    • John W. Moore University of Wisconsin - Madison, Madison, WI 53706
  • Video
    • Steven D. Gammon University of Idaho, Moscow, ID 83843
  • Text
    • Kelly Houston Jetzer University of Wisconsin - Madison, Madison, WI 53706
    • John W. Moore University of Wisconsin - Madison, Madison, WI 53706