Like eggshells and limestone, chalk is made of calcium carbonate, so it too reacts with acids to make carbon dioxide and calcium salts. The carbon dioxide bubbles out of the solution, while the calcium salt remains behind dissolved in the water. Stronger acids will give you a much faster reaction and more dramatic results; vinegar is a relatively weak acid, but you can dissolve chalk in it nonetheless. This project makes for a simple and fun science experiment, especially if you try comparing the reaction with vinegar to reactions with other weak acids such as lemon juice.
- Drinking glass
- Vinegar
- Small piece of chalk
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Instructions
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1
Fill the glass about half-way with vinegar.
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2
Add the piece of chalk. It shouldn't be long before you see bubbles forming on its surface. These bubbles are carbon dioxide gas, just like the bubbles from a mixture of vinegar and baking soda. This reaction, however, is a much slower one.
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3
Put the glass in a safe location where no one will knock it over and watch it over the next couple days to see how quickly the chalk dissolves.
