crystals diffusion membranes osmosis Salts sodium silicates Solubility
Age Group
12 13 14 15 16
Expected time
2 periods
A chemical garden.PDF
beaker symbol

Chemical garden

What’s the mystery? The chemical garden is a well-established experiment from the chemistry of salts, solubility, diffusion, and solutions. The nice thing is that if metal salts are put in sodium water glass solution, it can lead to an effect reminiscent of plants growing. This growing process can be observed and analysed. In the end, the experiment looks like a wild garden.
Domain(s) Chemistry
Subdomain keywords Salts, crystals, solubility, diffusion, membranes, sodium silicates, osmosis.
Age group 12 to 16 years old.
Expected time for the mystery Approximate time for teacher preparation: 15 min.Approximate time in classroom: 90-min lessons.
Safety/supervision Lab coat and safety goggles.Disclaimer: the authors of this teaching material will not be held responsible for any injury or damage to persons or properties that might occur in its use.
Preparation and list of materials Sodium water glass solution, iron(III)chloride, copper(II)sulphate, copper(I)chloride, calcium chloride dihydrate, potassium permanganate, water, sand, plastic beakers (20ml and 200ml), glass beakers (200ml), glass rod, test tubes, test tube rack, test tube holder, heating plate, graduated cylinders (10ml and 25ml), spatula, thermometer, magnifying glass, microscope, petri dishes.
Learning objectives Students will learn about salts, solubility, semi-permeable membranes, diffusion, and osmosis.
Resources Brandl, H. (1998). Trickkiste Chemie. Bayerischer Schulbuch Verlag, München.