Sour taste is the body's way of identifying acid, so if your candy tastes sour, it contains acid.
Pixy Stix acid test:
adding baking soda causes bubbles
adding baking soda causes bubbles
To test for acid yourself, try this:
What you need:
- Fruit-flavored or sour candy, such as LemonHeads, Nerds, WARHEADS, or sour gummy candy
- Baking soda
- Dissolve the candy in a small amount of warm water (about a half-cup or less). For hard candy like Smarties, you may want to crush it first to make it dissolve faster.
- Sprinkle a spoonful of baking soda into water.
- Watch for bubbles. If it bubbles, the candy is acidic.
When you dissolve acidic candy in water and add baking soda, the reaction produces carbon dioxide gas. This is what makes the bubbles.
For more fun, try testing candy like Skittles, StarBursts, or Sweet Tarts. Do these candies contain as much acid as really sour candies?
*If the candy is taking too long to dissolve, try crushing it first. You can also get quick results using Pixy Stix or candy covered by sour powder.
Video results: watch acid tests on Youtube
Explanation based on author's interview with Walter Bowyer, chemistry professor at Hobart and William Smith Colleges
Were there a lot of bubbles? We saw a few and not for very long. Some there were no bubbles at all. Curious to know what your results were.
ReplyDeleteIn general, the more sour your candy, the more bubbles you will get (because it contains more acid). Skittles and Starbursts produce a few bubbles, Nerds produce more, and sour coated candy such as Warheads and Sour Patch Kids produce the most.
ReplyDeleteUnless the sour coating is on the outside, make sure the candy dissolves before you add the baking soda. If the whole candy is sour, the more it dissolves the more bubbles you will see when you test it.
You might invite your child to sort the candy by predicting which will produce the most bubbles, based on how sour they are. Then dissolve each candy in a separate cup and add baking soda to test your predictions.
I adore your site! I just posted a link to yours on my blog: creatingcuriouskids.wordpress.com Here's to candy science!
ReplyDeleteCurious kids are what got us started on candy experiments in the first place, so hooray for scientific curiosity. Thanks for the note!
ReplyDeleteRachel of Momma Owl's Lab just tried the acid test at home, expanding it by 1) testing Smarties in baking soda water vs. plain water, 2) testing crushed vs. uncrushed to teach about surface area, 3) suggesting hot vs. cold or 4) suggesting 1 cup of water vs. a few TBSP. All great ways to learn about reactions. You can see her full entry at http://mommaowlslab.blogspot.com/2011/11/science-thursday-smarties-science.html
ReplyDeleteI've been trying to keep my online experiments simple so they're easy to follow, but my book Candy Experiments, coming out next year, will have lots more of these kinds of experiments. Don't worry, they'll still be fun!
does normal cabbage work too?
ReplyDeleteIf you're asking about making a cabbage indicator to test for acidity, the cabbage needs to be purple so that you can see the color change. It's pretty easy to do--chop up some purple cabbage and boil it, then strain it and keep the water as indicator (or, if you have your kids do it, have them rip up the cabbage and let it soak in water for an hour). When you add acid to the indicator, it should turn pink; if you add a base (like baking soda) it should turn blue.
ReplyDelete