posted by Tree Frog Treks! on Feb 2
This week students will learn all about acids and bases. Acids and bases are everywhere including liquids you drink, fruits, and even in your body. Scientists use something called the “pH” scale to measure how acidic or basic a liquid is. The scale goes from “0″ to “14″ with 7 being neutral (distilled water is an example). Acids typically range between “0″ and “7″ and bases range from “7″ to “14.”
Here are some common bases: baking soda, borax, ammonia
Here are some common acids: vinegar, lemon juice, battery acid
Let’s make some “Invisible Ink!”
Q-tips, toothpicks, or small brushes
1) Mix about 1/4 cup of baking soda and 1/4 cup of water.
2) Write using a q-tip, toothpick, or brush on a piece of paper.
3) Let it dry completely (the ink must dry completely before the message is revealed).
4) To read the secret message, paint grape juice concentrate across the paper with a paint brush or a sponge. Don’t forget grape juice stains.
Why does this work? Grape juice has an acid that reacts with the baking soda. A different color appears where ever the secret message is written.