Endothermic Reactions of Hydrated Barium Hydroxide and Ammonium
Chloride
Procedure
Place 32g Ba(OH)2 in a 250ml Erlenmeyer flask, add 11g NH4Cl;
close the flask and shake gently to mix. In about 30 seconds, liquid
will form in the flask. If the flask is opened, ammonia (NH4)
can be smelled.
Wet a small wooden block with a squirt of water and set the flask
on it. The flask will freeze to the wood.
Reactions
Ba(OH)2 * 8H2O (s) + 2 NH4Cl
(s) --> BaCl2 * 2H2O (s) + 2 NH3
(aq) + 8H2O (l)
Hazards
Both barium hydroxide [Ba(OH)2] and ammonium chloride [NH4Cl]
are toxic as well as irritating. Open and weigh both in the hood and
take only the measured quantities to the demonstration area in
closed containers.
Waste Management:
Close the demonstration flask and return to the stockroom. The
waste from this demonstration will be labeled for pickup by EH&S
(Toxic).
Official Web Page of the University of California, San Diego
For questions or comments contact webmaster@chem.ucsd.edu
Last Updated: 5/23/02
.gif){kind=spacer}
