As a conductive solution, you can use any electrolyte, whether it be an acid, base or salt solution. The lemon battery works well because the lemon juice is acidic. Try the same setup with other types of solutions. You can try this with potatoes, as they contain dilute sulphuric acid in small quantity.
Materials you need:
Metal salts of the transition metals, form precipitates when placed in the sodium silicate solution. As the metal salt dissolves, the resulting solution is less dense than the surrounding silicate solution and so rises up through the solution. As it reacts with the silicate anion, 'stalagmites' (like those found in caves) form from the bottom of the tank upwards - these are insoluble metal ion silicates. The surfaces of these insoluble silicates behave as a semipermeable colloidal membrane, across which osmosis can occur.
CHEMICAL GARDEN ( silica garden )
A Chemical garden is based on the process of crystal growth in 1 % solution of sodium silicate ( water glass ). It is a garden with non-living plants but is very attractive. Its a beautiful chemical experiment which is based on the phenomenon of osmosis. One more concept is lying here that most transition metal silicates are insoluble in water and are coloured.
Materials you need:
- One glass jar or aquarium tank
- Distilled water
- sodium silicate solution (1%)
- chromium (III) chloride hexahydrate crystals (green)
- Iron (III) chloride crystals (orange)
- Iron (II) sulphate crystals (green)
- Copper (II) sulphate crystals (blue)
- Nickel nitrate crystals (green)
- Manganese Chloride ( pink )
- Alum crystals (white)
- Cobalt(II) chloride crystals (purple)
HOW TO DO THIS : First of all place a thin layer of sand at the bottom of glass beaker/glass tank. Now prepare 1% solution of sodium silicate in distilled water and pour it into the glass tank. Now drop the crysyals of various coloured salts carefully into this solution leaving a bit of space between them. In a few hours hollow tubes of metallic silicate gets shootup from these crystals which look like trees. If you add too many crystals the solution will turn cloudy and immediate precipitation will occur. A slower precipitation rate will give you a nice garden. Once the garden grown , you can replace the sodium silicate solution carefully with pure water.
Mechanism behind this :