photo, ammonium dichromate volcano

A miniature volcano occurs when (NH4)2Cr2O7 is decomposed!

This mini volcano is analogous to a cinder/spatter cone.

Click on the small pictures to see the video. The file will open in a new browser window.

small photo, lighting volcano with bunsen burner
Video for Windows		 small photo, lighting volcano with bunsen burner
Quicktime		 Ammonium dichromate, (NH4)2Cr2O7, is an orange crystalline solid at room temperature. It can be ignited with high heat, such as that from a bunsen burner.
small photo, volcano burning
Video for Windows		 small photo, volcano burning
Quicktime

The orange (NH4)2Cr2O7 is decomposed according to the equation below:

(NH4)2Cr2O7(s) ----> Cr2O3(s) + N2(g) + 4H2O(g)

 

The dark green solid "volcano" is Cr2O3.

Note: This is quite toxic...

Mirrored from the U. Illinois Dpt. of Chemistry