Salt & Vinegar Crystals Printer Version

Salt and Vinegar Crystals

This easy project lets you grow some crystals using materials almost everyone has at home.

Materials

• 1/4 cup table salt
• 2 teaspoons vinegar
• 1 cup water
• Shallow dish, jar lid, or container
• Storage container
• Sponge
• Scissors

Instructions

1. Cut a sponge so it fits in the bottom of the dish, container, or lid. Put the sponge in the bottom of the dish.
2. Boil water. Remove from heat, and add a generous 1/4 cup of salt a little at a time. Stir well after each addition of salt.
3. Add vinegar. Stir well.
4. Pour the salt and vinegar mixture carefully over the sponge, just enough to cover the bottom of the dish. Pour the extra mixture into a container and save.
5. Put the dish in a safe, sunny place. After a few days, salt crystals will start to form. If the salt and vinegar mixture evaporates, add more.

What’s Happening

Salt is what we call the mineral halite. You boil the water because you can dissolve more salt in hot water than in cold water. As you add more and more salt, you will find that eventually no more salt will dissolve in the water. The sponge soaks up the salt and vinegar mixture. As the solution evaporates, salt crystals are left behind on the sponge. What shape are your salt crystals?