Question 15
Work in groups to produce crystals of sodium chloride. Follow these steps.
1. Add several teaspoons of table salt to a jar of water. Stir until all the salt dissolves. Repeat this until no more salt will dissolve in the water.
2. Pour the saltwater into an evaporation dish.
3. Place the evaporation dish on a tripod stand and heat it over a Bunsen burner.
4. Wait for the water to boil and evaporate.
5. When most of the water has evaporated, turn off the Bunsen burner.
6. Leave the evaporation dish to cool.
7. What do you observe after a while?
**Caution (from the book)**
- Be careful when heating the evaporation dish.
- Wear safety goggles.
- Do not touch the evaporation dish when it is hot. It may burn you.
**Additional safety guidance:** Carry out heating only under teacher supervision.
1. Add several teaspoons of table salt to a jar of water. Stir until all the salt dissolves. Repeat this until no more salt will dissolve in the water.
2. Pour the saltwater into an evaporation dish.
3. Place the evaporation dish on a tripod stand and heat it over a Bunsen burner.
4. Wait for the water to boil and evaporate.
5. When most of the water has evaporated, turn off the Bunsen burner.
6. Leave the evaporation dish to cool.
7. What do you observe after a while?
**Caution (from the book)**
- Be careful when heating the evaporation dish.
- Wear safety goggles.
- Do not touch the evaporation dish when it is hot. It may burn you.
**Additional safety guidance:** Carry out heating only under teacher supervision.
