Purple Brew: An Acid-Base Indicator

Next time kids say they don’t like vegetables, try out an experiment that will bring out the fun side of our leafy friends. Mom and Kiddo of  the blog What Did We Do All Day? shows us how to play with color in this demonstration that uses an acid, a base, and a vegetable. She suggests keeping some of the solution in the fridge for a rainy day and allowing kids to experiment on their own.

You will need:

• purple or red cabbage
• small and large glass jars
• baking soda
• water
• vinegar
• measuring cup
• 1/4 teaspoon

What to do?

1. Chop up a cabbage and simmer on the stove for 20 minutes to make a cool purple liquid (kids, please let a grown-up do this)
2. After the purple brew has cooled, collect some small and large jars. Place about 1/4 tsp baking soda and 1/4 tsp water in one jar, a small amount of vinegar in another and about 1/4 cup purple brew in a third.
3. Put some of the brew in a measuring cup and pour 1/4 tsp of the brew in each of the first small jars. What happens when you mix the purple brew with the different solutions?
4. In the jar filled with a 1/4 cup of purple brew,  pour about 1/4 cup vinegar. What happens?
5. Next, add 1/4 tsp baking soda to the same solution. What is your observation?

How does it work?

Red cabbage contains a chemical called flavin and flavin has the ability to change color based on the pH level of certain liquids. Nuetral solutions, (like water) are purple. Acid solutions, like the vinegar, turn will turn flavin red. Basic solutions, like the baking soda water, become blue.

You can check out Mom and Kiddo’s full post of this experiment HERE. Let us know what your results are when you make your own purple brew. What would happen if you tried different vegetables? What would happen if you used cream of tartar, lemon juice, salt, lemonade, or other materials from your kitchen pantry? Can you make your own litmus paper and test the pH of the solution?

Eggshell Geode Crystals

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This project comes to us from Melissa Howard who is a Mom, Blogger, and photographer. This project nicely demonstrates how real-life geodes are formed in igneous and sedimentary rock. It also demonstrates super-saturated solutions and shows a nice variety of crystal shapes and formations.

YOU WILL NEED:

• clean eggshells
• water
• a variety of soluble solids: table salt, rock salt, sugar, baking soda, Epsom salts, sea salt, borax, or cream of tartar
• small heat proof containers (coffee cups work well)
• spoons
• food coloring
• egg cartons and wax paper or mini-muffin tins

WHAT TO DO:

1. Crack the eggs for this project as close to the narrow end as possible. This preserves more egg to use as a container for the solution.
2. Clean the eggshells using hot water. The hot water cooks the lining and allows you to pull the skin (egg membrane) out of the inside of the egg using your fingers. Make sure to remove all the egg membrane, if any membrane stays inside the shell it is possible that your eggshell will grow mold and your crystals will turn black.
3. Use an egg carton lined with waxed paper or mini-muffin tins to hold the eggs upright.
4. Use a saucepan to heat the water to boiling. .
5. Pour half a cup to a cup of water into your heatproof container. If you poured half a cup of water into the container, add about a ¼ cup of solid to the water. Stir it until it dissolves. Likewise if you used a cup of water, add about ½ a cup of solid to the water. You wanted to add about half again the volume of the water as a solid to the mixture. When the initial amount of solid is dissolved continue adding small amounts of the solid until the water is super-saturated. Super-saturated simply means the water has absorbed all it is able to absorb and any solid you add will not dissolve.
6. Add food coloring.
7. Carefully pour your solution into the eggshell, filling it as full as possible without over-flowing it or causing it to tip.

Find a safe place to put your shells while the water evaporates. Crystals will form inside the eggshells as the water evaporates.

HOW DOES IT WORK?
Dissolving the crystals in hot water created what is called a “super-saturated solution.” This basically means that the salts took advantage of the energy of the hot water to help them dissolve until there was no more space between molecules in the solution. As the solution cooled, the water lost its energy and the crystals are forced from the solution to become a solid again. Since this happens slowly along with the evaporation, the crystals have time to grow larger than they were when the experiment started. Natural geodes in rock are form in much the same way as mineralized water seeps into air pockets in rock. This is also how rock candy crystals are formed.

You can visit Melissa’s great blog and see more pictures HERE.

Halloween Science Experiments & Ideas!

Need ideas for your Halloween party, or just some all-around Halloween fun? Here’s a few great ideas to get you started.

GLOWING DRINKABLE BEVERAGES
Did you know that tonic water will glow under a blacklight? We didn’t either. The quinine in the tonic water glows a very cool looking blue color that we really like. If you’re not crazy about the taste of tonic water,  try making ice cubes using the tonic water and then add them to a glass of Sprite or another light colored citrus drink. Switch on the blacklight and you have the perfect Halloween beverage. After a few minutes the entire drink will start to glow. (see photo)

MAKE SOME HALLOWEEN SLIME
Slime and Halloween go together like, well, slime and Halloween. Here’s 2 ways to add a little slime to your October.
Do it yourself slime - If you’ve got a little glue and some powdered borax, you can easily mix up some slime by following the instructions HERE.

Slime Kits - If you want to make LOTS of slime as an activity, or if you have trouble finding Borax, a kit may be the way to go. We have just the slime kits you are looking for. You can find out more by clicking HERE.

EERIE GREEN PUMPKINS
All your neighbors will have Jack-O-Lanterns that glow orange, but you will impress them with a Jack-O-Lantern that glows green! Best of all, the green glow is simple and safer than traditional candles. Purchase one or two large glowing light-sticks per pumpkin at a party store or hardware store. (We like green, but there are many colors to experiment with) Activate the light stick and simply drop them into the pumpkin, or, to conceal the glow sticks, attach them to the inside of the pumpkin lid by unbending large paperclips to secure them. Place your pumpkin outside on Halloween night and admire the “Oooos” and “Ahhhhs” of Trick-Or-Treaters.

MAKE A HAUNTED, SCREAMING CUP
If you think haunted houses are scary, wait until to hear…haunted drinkware! First, check out our Chicken In A Cup experiment, but instead of pulling along the string in short bursts to sound like a chicken (it really does, trust us) pull in one continuous motion. The result is an eerie screaming cup! The only thing better than than trying the screaming cup yourself, is trying the screaming  cup with LOTS of your friends all at once.  Parents especially seem to enjoy that. The  instructions can be found HERE.

BUBBLING POTIONS AND JARS
Every mad scientist needs some bubbling potions. While dry ice may be the ultimate bubbling potion, the effect tends to be short-lived, and dry ice can be dangerous around younger Halloween party goers. The solution is a simple aquarium pump. Purchase an inexpensive aquarium pump and some tubing at your local pet store along with a line splitter (if you want more than one bubbling potion.) Set up the pump to send bubbles into various large food jars through the tubes. Add some food coloring, plastic bugs or fake body parts, and you’ve got the sights and sounds of a mad scientists lab that will last all night. For added drama, light up the jars from below using flashlights. You can also create floating eyeballs by drawing an iris and pupil onto ping-pong balls with permanent markers. Make a few that will float around by drilling two very small holes in the ping-pong balls and allowing them to fill with water until they sink. For an added glowing blacklight effect add our Glow-Bright Concentrate.

GHOST BUBBLE SPHERE
If you’ve got some dry ice, (available at some grocery stores and most ice companies) why not gather Halloween party-goers and try your hand at making a large dry ice ghost bubble? You will need:

• Medium size bowl with a rim
• Small bowl
• Liquid soap
• 20 inch by 2 inch strip of absorbent cloth (cotton or cheese-cloth work well)
• Dry Ice

Fill each bowl halfway with water. In the small bowl, add a good squirt of liquid soap (we like Dawn Concentrate) and stir it up. Dip the cloth into the soapy water to get it wet. Get the rim of the larger bowl wet with water and add the dry ice . Admire the sights and sounds of bubbling dry ice. Now the tricky part, pull the cloth strip so that it is taught and pass it across the entire rim of the medium bowl to create a soap bubble “skin” over the bowl. It may take several tries. Once you get it, the bubble will expand as gas is released and it will rise to create your own ghost bubble sphere.  After the soap gets into the water with the dry ice, you are treated to soap bubbles filled with dry ice mist! CAUTION: Never touch dry ice! It’s -109° F (-78° C) That’s really, really cold.

CLICK HERE for instructions to make a static powered dancing ghost.

THE SCREAMING QUARTER EXPERIMENT

If you have some dry ice from the Ghost Bubble Sphere left over, you might want to try this fun little demonstration. Dry ice is the solid form of carbon dioxide. As it sublimates, (turns back into a gas) the carbon dioxide gas escapes around the quarter causing the quarter to vibrate and make a rather spooky shrill along with occasional humorous sounds. Always wear gloves when performing this demonstration.

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FOR  HALLOWEEN RELATED ITEMS
FROM OUR NEW STORE, CLICK HERE.

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