Skip to main content

Endothermic Reactions of Hydrated Barium Hydroxide and Ammonium Chloride


250 mL Erlenmeyer Flask

Bottle of Barium Hydroxide (32g - premeausred)

Bottle of Ammonium Chloride (11g - premeausred)

DI water Rinse Bottle

Small Block of Wood

Gloves and Goggles




Place 32gms Ba(OH)2 in a 250ml Erlenmeyer flask, add 11gm NH4Cl, and shake gently to mix. In about 30 seconds, ammonia can be smelled and liquid will form in the flask.

Wet a small wooden block with a small squirt of water and set the flask on it. The flask will freeze to the wood.



Ba(OH)2 * 8H2O (s) + 2 NH4Cl (s) --> BaCl2 * 2H2O (s) + 2 NH3 (aq) + 8H2O (l)


Waste Management

The leftover solution should be poured into a bottle and sent to EH&S as hazardous waste (Toxic).