Melting Ice Science Experiment with Salt and Color

Share & Comment

Melting Ice Science Experiment with Salt and ColorMelting ice with salt and then adding liquid watercolors is a simple kids’ science experiment that we’ve done before. But sometimes you have to try something more than once to really get it right. Last time our melting ice science experiment was so much of a salt and watercolor free-for-all that we couldn’t see what was happening to the ice under all the salt.

This time we got it right. And it truly is a beautiful and fun learning experience.

Melting Ice Science Experiment with Salt and Liquid Watercolors

MATERIALS

INSTRUCTIONS

Melted Ice Science Experiment 04

For fun, and for experiment’s sake, I filled many different sizes of bowls with water and left them to freeze overnight. I recommend this!! Not necessarily the many part, but if you do this, try for 2-3 different sizes. And keep at least one of them shallow. The tupperware container you can barely see in the back of the photo above was great for this.

Melted Ice Science Experiment 05

The next morning I loosened the ice from the bowls with a little warm water and set them in a big plastic finger paint tray with a lip (from Discount School Supply). I remembered how much the ice melted last time —it’s the point, right?! —and didn’t want a salty, painty mess all over my table. A baking tray with sides would work. I set our tray over an old towel for extra protection.

Ice for Science Experiment 06

Maia’s friend Stella was over for the morning and the three girls were very excited about the melting ice science experiment! I gave them each a bowl of table salt (the cheap Morton’s salt) and they sprinkled it over the tops of the ice domes.

Two notes:

  1. Rock salt, or another coarse salt, would be good to try as well, but we didn’t have any. (I did have some sea salt in the kitchen, but felt it was too expensive to use like this.)
  2. Also, I purposely gave them each a modest amount to sprinkle since I didn’t want a repeat of the salt dumping excuse for a science experiment we had last time.

Salt on Ice Science Experiment 08

They got excited when they first noticed the little ravines down the side of the ice where the salt was melting it!

Melting Ice Science Experiment 11

Once we could tell that the salt was melting the ice, I got out the liquid watercolors. I squeezed a little bit of a few different colors (yellow, pink, purple, turquoise) into jelly jars and added a dropper to each.

Note: You can also use food coloring for this project. The color selection may be more limited, but it works just as well.

Melting Ice Science Experiment 15

The girls squeezed the watercolors onto the ice.

Melting Ice Science Experiment 17

Daphne had just as much fun with it as the older kids did, but it took her a few tries before she figured out the droppers (when to squeeze and when to release).

Ice Science Experiment 19

The color is beautiful on its own, but the real reason for adding the liquid watercolors is to highlight the ravines, crevasses, and tunnels that are forming in the ice as the salt melts it.

We talked about how the salt melts the ice, both before and during the science experiment. Since it was a hot summer day, we agreed that the ice would melt anyway. But then we talked about how salt makes ice melt differently. That it will melt ice at much cooler temperatures, and so wherever the salt touched the ice it would melt faster than the rest of the ice.

Melting Ice Science Experiment 23

The swirls of liquid watercolors in melted ice water were beautiful, too!

Melted Ice Science Experiment 27

In fact, we had A LOT of melted ice water. The girls took turns with a turkey baster to suction the water out.

You don’t have to take the water out, but I thought it would be easier to see all the exciting tunnel action if the ice wasn’t swimming in a lake. Also, our handy dandy plastic tray was cracked along the lip and I didn’t want the water to reach that level. Plus the kids thought that using the turkey baster was as fun as the rest of the project.

Melted Ice Science Experiment 28

Even Daphne had to take her turns with it!

Melted Ice Science Experiment 30

Look! A colored ice suncatcher!

We took a few of our ice pieces out on the porch to look at them in the sunlight. The watercolors really helped to highlight where the ice was melting! We oohed and ahed for a while. They were beautiful.

Melting Ice Science Experiment 34

From the bottom of the shallower ice pieces, you could see a whole bunch of tiny bubbles of color where the mixed salt and watercolors were pooled as they slowly ate away and melted the ice. We thought that was SO cool!!

Melting Ice Science Experiment 38

After our break to admire the ice in the sunlight, we brought them back in and turned each over. We wanted to see what it would be like if we melted tunnels and ravines through both sides of the ice. So we added more salt (yes, there was some salt dumping action this time—mostly on Daphne’s part), let it melt awhile, and then added liquid watercolors.

Note: Some of the salt (especially where it was dumped) had hardened into a solid mass. We chipped those away before adding the liquid watercolors, because we really wanted to be able to see the ice tunnels.

Melting Ice Science Experiment 41

Just for variety’s sake, we brought out different colors of the liquid watercolors: red, blue, and gold (the metallic gold paint was pretty amazing!).

Melting Ice Science Experiment 44

I LOVED seeing how into this science experiment the girls were!

Melted Ice Science Experiment is Beautiful

And the results were beautiful and interesting! You can see that the salt ate away at both sides of this ice piece so that there are holes through the middle.

Melted Ice Suncatchers

We took all the ice outside and admired them in the front yard as they continued to melt.

Melting Ice Science Experiment for Kids

This melting ice science experiment is one worth doing (and repeating). I hope you try it! And if you’ve tried it before, give it another go!

P.S. Want more science? Here’s my current collection of fave artful kids science experiments

This post contains affiliate links.

Share & Comment

Comments

  1. says

    These are beautiful! I did another science experiment with ice and salt this summer that was really interesting – though not pretty. :-) We made up a bowl of ice, a bowl of ice water, a bowl of ice with lots of salt, and a bowl of ice water with lots of salt – then took the temperatures of the different mixtures. The ice and salt got down to 14 degrees F! The kids were amazed – and then we made ice cream in small ziplock baggies locked inside larger ziplock baggies filled with the ice and salt mixture. Yummy science fun!

  2. Andrea says

    Beautiful! We did this activity in milk cartons (based on your previous post), but I love your fine tuning.

  3. says

    <3 We did this! Aria loved it but she was a bit distraught that we couldn't keep it forever. I used it as a learning opportunity to talk about the beauty of things that are only temporary and how important it is to enjoy them while they last. :D

  4. says

    I get it about wanting it to last as is. That’s one reason we take photos to document the more ephemeral art we do — it’s a way of keeping it and looking at it again later. Of course, I take a ton of photos for the blog, anyway…. :)

  5. Carly says

    Here’s an ice cream in a bag recipe. I can’t wait to try it. http://innerchildfun.com/2012/06/ice-cream-in-a-bag.html
    I live in Winnipeg, Manitoba, Canada and my kids have had the pleasure of seeing salt melt ice when I have to sprinkle it on the front path in the winter so the mail carrier doesn’t slip! This would be a fun way to give them a hands on version.

  6. says

    That looks like a fun experiment!
    The liquid watercolors from discount school supply are so rich and vibrant. We used them (with droppers) to color in the snow last winter. It was fun :)

  7. Nancy says

    It would be interesting to try this with coarse rock salt that is used outdoors in winter, as well as the salt that is used in water softeners, kosher salt and standard table salt. I love the idea of using liquid watercolours to highlight the melting action. I’ll have to try this with my boys, but first I have to clear out some ice cream in my freezer to make room!

  8. says

    We haven’t tried liquid watercolors on snow! I’ll definitely add it to the list for this winter! Did you do it outside or bring a basin of snow in?

  9. says

    Ha! Yeah, I had to do some serious juggling and cramming to get the bowls of water to fit in our small freezer. And yes, it would be interesting to try this with a few different kinds of salt. Especially if you kept them separate — one kind per ice piece — so you could really see the differences.

  10. beccy says

    I used this idea with my nursery class whilst being observed by my head teacher. I was told that the lesson was outstanding! Thank you!!

  11. sarah says

    We just did this without the watercolors, so now we need to do it again! My son collected rock salt from the road to start the project, so we used table salt, “road” salt, baking soda, hot air, hot water and a control to see what would work the fastest. I have a boy, so everything is a race :) I love the watercolor though and it would be great during a cold spell so the blocks would last a while outside. We also use the liquid watercolors on the snow with spray bottles. a little in the bottom with the rest water goes a long way and still makes a reasonably dark color. My kids will empty at least 3 bottles each on the snow. Thanks again for all your wonderful ideas!

  12. Robby Stanley says

    You might also want to explain more in detail about the science behind this experiment. My wife and I homeschool, so we’re big fans of simple science experiments where you can adjust your science explanation to suit the ability levels of the students.
    The two main points are color mixing and why the salt melts the ice.
    While color mixing is pretty straightforward (additive/subtractive color mixing), the salt aspect isn’t.
    The freezing point of water is 0degC. But the freezing point of salt water (varying based on salt content) can be as low as about -21degC.
    By adding the salt, you are essentially allowing the salt to mix at the microscopic level with the water at the surface of the ice block to become salt water. Since the salty combination requires a much lower temperature to remain solid ice, it will melt at room temperature or even at 0 deg C.
    Take sprinkling salt on icy sidewalks, for example. If the temperature outside is -10 deg C, you can sprinkle enough salt so that it would take an environment of -15 deg C for it to remain frozen (you could measure, but just keep adding salt until it melts). Thus, it would melt at -10 deg C.
    There’s much more science that can be said on this topic, but this is a basic idea of what’s going on.
    If you’d like to explore the concept further, it’s called colligative properties. Basically, the properties of water (or any solution for that matter) change when you add stuff (salt, spices, antifreeze, etc.) to it.

  13. says

    Hi – I pinned this a while back and we just did it – it worked so well! Thank you so much for your super-clear instructions. We did the variety of containers you suggested and used liquid watercolours. I also tried it with gel food colour, the results were lovely but they quickly saturated the ice so I think the children had more fun being able to add LOADS of watercolour!
    I blogged about it here – http://www.navigatingbyjoy.com/2013/05/11/creative-science-with-ice-salt-and-colour/
    (and linked back to you)
    Thanks again!
    Lucinda

  14. Barb says

    I’m going to try this for sure! In looking at all of your pictures, I kept waiting for your young friend’s white dress to meet it’s maker, so to speak!! It didn’t seem to! I know I won’t be able to say the same for my children’s clothes!

  15. Barb says

    Thank you Robby Stanley! I knew the basics of freezing points, etc., but had forgotten the term “colligative properties!” I am homeschooling 3 grandchildren. We plan on doing this Monday!

  16. Barb says

    Gorgeous pictures! Thanks for posting many! Looks like great fun, and I have my freezer full of plastic bowls of water now, for Monday!

  17. says

    Eliana- You should try this too get a water bottle and make ears on the top of it and 2 eyes with buttons and open the water bottle hole
    and add money in it as a cool piggy bank! Snow whould be awsome to have in California thats a good idia!