"Christmas Mood" experiment
How to make beautiful "hoarfrost" with benzoic acid
Do you miss winter already? Then we’ll show you how to make your own winter wonderland with the help of chemistry.
Reagents and equipment:
- 15 g of benzoic acid;
- a large beaker;
- fir branches;
- dry fuel.
Place a large beaker on a special stand. Add 15 g of benzoic acid and 3-4 fir branches. Place dry fuel under the glass beaker and light it. After a while the beaker will heat up so much that the benzoic acid will start to sublime, i.e. move from a solid to a gas phase, without passing through a liquid phase. As soon as all the benzoic acid evaporates, remove the fuel and let the beaker cool down. When it has cooled down, the benzoic acid vapor will start to settle on the fir branches and the walls of the beaker. It really looks like it’s snowing!
In this experiment, solid benzoic acid evaporates without passing through a liquid phase. The process of moving from a solid phase directly to a gas phase is called sublimation. When the crystals of benzoic acid heat, the temperature increases, the crystals melt, and the transition to a gas phase takes place. Cooling causes a reverse transition. When the benzoic acid vapor settles on the fir branches, it cools and crystalizes. The reverse process of transition from a gas phase to a solid phase is called desublimation.
In working with benzoic acid, wear rubber gloves and protective glasses. Stay at a safe distance from the source of fire and observe fire safety.
Warning! Only under professional supervision.