Engraving at home
How to make make inscription on spoon using electricity
Does engraving seem too complicated and specialized to try? Here’s a simple way to engrave a spoon at home!
- Attention! Observe safety precautions when working with fire.
- Conduct the experiment only under adult supervision.
Reagents and equipment
- spoon (stainless steel recommended);
- sodium chloride solution (2 Tbsp salt in 200mL water);
- 2 cups;
- 2 tea lights;
- aluminum container;
- battery with 4 AAA batteries;
- 2 crocodile clip wires;
- wooden stick;
- hot water;
- paper towel.
Melt the candle wax in the aluminum container and coat your spoon with it, leaving one area bare – you’ll need to connect a crocodile clip to it later. When the wax hardens, use a wooden stick to scratch an inscription or drawing through the wax down to the metal. Add 2 tablespoons of table salt to a glass of water and mix until completely dissolved. Lower the wax-covered segment of the spoon into the solution. Connect the spoon to the positive electrode using a crocodile clip. To close the circuit, put the crocodile clip wire connected to the negative electrode in the salt solution. Observe as a gas is released and a sediment forms. Wait ten minutes. To remove the wax, immerse the spoon in hot water for 2 minutes and wipe with a paper towel – your drawing should be etched in the metal.
When sodium chloride NaCl dissolves in water, it decomposes into Na+ and Cl- ions. This process is called dissociation, and is what allows such a solution to conduct electrical current. When the spoon is connected to the battery and the circuit is closed, ions move and an electric current flows through the solution. The bare metal dissolves on the positive electrode, and hydrogen gas is released on the negative electrode. The process occurring on the positive electrode is:
Fe⁰ - 2e = Fe²⁺
Fe⁰ - 3e = Fe³⁺
The process occurring on the negative electrode is:
2H₂O + 2e = H₂↑ + 2OH⁻
Another chemical process also occurs in the solution: the resulting reaction products interact with each other and precipitate as iron(II) and (III) hydroxides.
Fe²⁺ + 2OH⁻ = Fe(OH)₂↓
Fe³⁺ + 3OH⁻ = Fe(OH)₃↓
When a substance chemically decomposes under the influence of electric current, this is known as electrolysis.