Ba(OH)2.8H2O (s) + 2 NH4SCN (s) --> Ba(SCN)2 (s) + 10 H2O (l) + 2 NH3 (g)
Here's what you need to use this reaction as a demonstration:
- 32g barium hydroxide octahydrate
- 17g ammonium thiocyanate (or could use ammonium nitrate or ammonium chloride)
- 125-ml flask
- stirring rod
- Pour the barium hydroxide and ammonium thiocyanate into the flask.
- Stir the mixture.
- The odor of ammonia should become evident within about 30 seconds. If you hold a piece of dampened litmus paper over the reaction you can watch a color change showing that the gas produced by the reaction is basic.
- Liquid will be produced, which will freeze into a slush as the reaction proceeds.
- If you set the flask on a damp block of wood or piece of cardboard while performing the reaction you can freeze the bottom of the flask to the wood or paper. You can touch the outside of the flask, but don't hold it in your hand while performing the reaction.
- After the demonstration is completed, the contents of the flask can be washed down the drain with water. Do not drink the contents of the flask. Avoid skin contact. If you get any solution on your skin, rinse it off with water.