ammonium dichromate*
. . . powder
. . . solid
ammonium bichromate
|
Tch
1
2
-
-
5
-
-
|
5.1
DHS
CW
Hazardous Chemical
|
II
|
1439
7789-09-5
|
Highly toxic if ingested or by skin contact, carcinogenic. Do not inhale particles. Use eye protection where splashes can occur. Decomposes on heating, producing toxic fumes.
Forms explosive mixtures with magnesium powder and other active-metal powders, and with combustible materials or organic compounds. Can be used for the "volcano experiment", in which a small quantity of the solid (<20 g) is ignited with a match or heated from above with a small bunsen flame; the solid expands to form an enormous pile of green chromium(III) oxide particles, releasing toxic fumes at the same time.
Carry out the volcano experiment on a ceramic tile in a fume cupboard, or outside in an area which can be cleaned up and where the students can be kept upwind. Teachers must be fully aware of the safety issues before performing the "volcano experiment" as a demonstration. Commonly used in aqueous solutions (<5%) to study ammonium and dichromate ions and redox reactions.
Q-Stores
42
See also HEAVY METAL COMPOUNDS,
OXIDANTS
and Appendix F.
|
