potassium nitrate to be purified. Put 500 ml of water in the 2 litre pot. Heat the pot containing the water over an electric or gas stove element and add approximately one half the potassium nitrate. Stir well to dissolve.
Potassium nitrate is a crystalline potassium salt of nitric acid. Many products use potassium nitrate in homes, agriculture and industry. Some examples include toothpaste, fertilizers, fireworks, pesticides and molten salt for solar power plants.