We’re going to take two everyday materials, salt and vinegar, and use them to grow crystals by creating a solution and allowing the liquids to evaporate. These crystals can be dyed with food coloring, so you can grow yourself a rainbow of small crystals overnight.
The first thing you need to do is gather your materials. You will need:
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It is best of the top of the water is level with the top of the sponge. Be sure to start with a slightly damp sponge. A dry sponge is more likely to float. In other words, run water over the sponge and squeeze out most of the water. The place the sponge in the dish and pour the solution over the sponge as shown in the video.
Is it ok if the sponge floats
That’s a good question! This is a good opportunity to think about why vinegar is used. Then, try the experiment with and without vinegar and make notes on the outcome.
What is the significance of using vinegar in this experiment? Does it change the crystals at all from when we made them with just water?
Yes, the solution may affect the pot and spoon. So you’ll need to use an old pot and spoon that will be reserved only for science experiments. You would no longer use them for food.
Will the solution damage the spoon and pot?
A sponge works best, but feel free to try a lava rock.
could i use a lava rock
No pipe cleaner won’t work. It needs to be something porous, so a sponge works best.
could i use a pipe cleaner????
If you don’t see any crystals after 24 hours, I recommend trying the experiment again from the beginning. Be sure you use a dish that is shallow and small enough so the liquid comes just to the top of your sponge. Also, remember that non-iodized salt works best.
we just did this experiment yesterday, about 24 hours ago. no crystals yet. anything i can do to get them forming?
Yes – I would try the ones you have side by side, and compare the results!
Will rock salt work?
You said non-iodized salt works “better”, will Himalayan salt work?
A very thin, hard to see crusty layer formed on the surface of our sponge, but the small crystals that formed on the sides of our glass pie plate were better. This took a very long time (a couple of weeks) and the crystals were not numerous or large. Did we do something wrong? The results of our crystal projects have been kind of underwhelming, and my kids are losing interest as I try to finish this unit. I notice that another family moved the location of their solution to get better results. Should I try a sunny spot? Our rock candy isn’t growing, either, even though we’re on our second try (added more sugar to the solution). The same with our solution that contained laundry bluing, salt, and ammonia. The crystals really never developed. I know I’ve asked several questions here… thanks!
ok 🙂
Thanks!!!!
No, but you should have a pot just for chemistry use, because some of the other experiments in this section will, and it’s a good practice not to mix chemicals with your food. 🙂
Will this experiment damage the pot that you use?
Thanks,
-Elias Pealer
Yes!
could you use a rag instead of a sponge?
Not quite… but it’s an interesting idea!
Would this be how they make the flavouring for salt and vinegar potato chips?
You need a weak acid to mix with the salt in order to form the crystals, and acetic acid is perfect for the job. 🙂
Why do we add vinegar to the solution?
Not a good idea to eat chemistry experiments, no matter how edible they may be. It’s not a good habit to start.
Are these edible?
Try food coloring!
Can you add color dye to it??? or will that mess it up??
Very cool!:P
I’ve had best results with distilled, but I’d encourage you to try out what you have and see how it works… who knows – you might figure out something new! 🙂
Do you have to use distilled vinegar?
Thanks
We did this and put it in our bathroom. It was not growing, so we moved it to the sun room, and then it started growing crystals. When we looked at the them under a magnifying glass, the top had lots of crystals but the bottom ones were cooler becuase they were square.