This Friday (June 11) we will explore the erupting realm of acid-base chemistry in our new video series for kids: Summer School with Live Science.
In this week’s installment, WordsSideKick.com producer Diana Whitcroft will demonstrate the reaction between sodium bicarbonate (baking powder) and citric acid (lemon juice, in this case). This fun experiment is a great way to introduce young minds to the world of chemistry.
Every Friday at 3pm EDT (12pm PDT) Diana hosts Summer School With Live Science, which you can find live on WordsSideKick.com̵
Disclaimer: It is strongly recommended that all scientific experiments, recipes and methods be tried only under the supervision of adults. Adults should handle or assist with potentially harmful tools and ingredients. Always wash your hands thoroughly after attempting any experiment. Avoid touching your face and eyes when performing experiments and, if possible, wear goggles or goggles. Do not ingest any of the ingredients during or after performing this experiment.
Lemon volcanoes: Materials
Age group: 5-10 years
- Tray or cookie sheet
- Paper (optional)
- Cutting knife
- Popsicle stick
- Fruit color
- Dishwashing liquid
- Baking soda
Step one: Prepare your workstation
Place your tray on a surface well covered with newspaper. Optional: Load paper on your tray; this is where you want to break out of your volcanoes, and if the paper catches the colorful liquid, you can turn it into a work of art.
Step two: Ready your lemon
Have an adult cut a small portion of the bottom of the lemon so that it stands upright. Then cut off the top of the lemon and expose the inside pulp and juice. Use your popsicle stick to mash the inside of the lemon so that the “meat” or the meaty inside is pushed all the way down and the lemon is mostly filled with juice. Be careful not to puncture the lemon peel.
Step three: Choose a color
Squeeze a few drops of your food coloring into your lemon. The amount of food coloring you use depends on the size of your lemon and how much juice it provides. Small lemons with very little juice: 2-3 drops. Large lemons with a lot of juice: 4-5 drops. Try different color combinations and see what comes out! You can even burst two or three lemons at a time to get a binder color effect on your paper. Then give a good spray of dish soap in your lemon.
Step four: Eruption your volcano
Sprinkle in your lemon a few teaspoons of baking powder with your spoon. Again depending on the size of your lemon you need to adjust the amount. Small lemons with a little juice: 2-3 tsp. Large lemons with a lot of juice: 4-5 tsp. Immediately you should see bubbling and effervescent, but it is likely that you will need to use your spoon or ice lolly to better mix the juice and baking soda. Your lemons are now starting to overflow with colorful bubbles.
Document this experience and send photos to us either on social media or to firstname.lastname@example.org. We would love to see your results so we can present them in our photo gallery!
Step Five: Template!
Now that the explosive fun is over, it’s time to get creative. Use your hands, a brush or even sponges to create your own artwork from the colorful liquid left on the paper. Just remove your lemons and go to town! Be careful not to overpaint your paper. If you combine your colors too much, your colorful canvas will turn into a big gray blob (unless of course you really like the color gray!).
The science behind lemon volcanoes
When baking powder was added to the lemon juice, it bubbled and foamed. This is because when sodium bicarbonate (baking powder) and citric acid (lemon juice) are combined, they react by forming carbon dioxide gas as well as a chemical compound called sodium citrate. It is carbon dioxide that causes all these bubbles (remember CO2 is the gas that causes your can of soda or seltzer water to burst). We know that carbon dioxide is the primary gas we exhale when we breathe. It occurs naturally in the Earth’s atmosphere and is emitted by natural sources such as geysers (and volcanoes) as well as industrial processes.
Sodium citrate is sodium derived from citric acid. It is used in a variety of everyday objects. It is used as an anticoagulant for blood products as well as an acidity regulator in food.