Here’s a great way to do some science and learn about some of the chemistry behind fireworks. I present: Black Snake Fireworks! Just in time for the fourth of July.
I’ve gotten lots of request for science activities related to the fourth of July and more specifically…FIREWORKS! Many of you wanted to know the science behind fireworks and if it is possible to create fireworks at home. In response to those requests, here is a great way to create some of those intriguing Black Snake fireworks that you see every year around this time. This activity requires the use of fire and some flammable liquids, so adult supervision and safety precautions are a must (make sure you have a fire extinguisher or sand nearby)!
Here’s What You Need
- Sand
- A high-percentage alcohol (ethanol) – I use grain alcohol (e.g. Everclear)
- Powdered sugar (sucrose)
- Baking soda (sodium bicarbonate)
- A grill lighter or long match
- Aluminum foil or a foil pie plate
Here’s What You Do
First, let’s start by making our baking soda and sugar mixture. In a bowl, mix 4 tbsp of powder sugar with 1 tbsp of baking soda. Once you have those two ingredients mixed well, place the bowl to the side. We will use in later. Create a mound of sand in the middle of the foil/pie plate. Use your finger to make an indentation in the middle of the mound of sand. This is where you will pour your alcohol and the other ingredients.
Measure 3 tsp of alcohol and carefully pour it into the indentation. Now, let’s add the baking soda and sugar mixture. There are a couple of ways that you can do this. Each way will give you a different kinds of snake(s). First, you can sprinkle 1 tsp of the baking soda and sugar mixture into the indentation in the sand mound. Another method is to pack 1 tsp baking soda and sugar mixture into the measuring spoon. This will create a little spoon shaped tablet that you can drop into the indentation in the sand mound. In either case, don’t pack the mixture down into the indentation.
Have an adult use a long match or a grill lighter to ignite the alcohol. The flame will initially be very hard to see (the alcohol burns blue). However, you will know it is lit when you see the baking soda and sugar mixture begin to blacken as it burns. You might also smell something very familiar – roasted marshmallows (that’s the sugar burning)! It will take a while before the snakes really start to grow, so be patient. After a while, you will see the baking soda and sugar mixture start to bubble. Slowly, the black snakes will start to grow from the sand! Make sure the flame is out before you attempt to touch or pick up the snake. When you’ve done it once, grad some more baking soda and sugar and do it again. Just make sure you mix your sand and reform you sand mound after each attempt. You will get different types of snakes each time!
The Science Behind the Black Snake Fireworks
When baking soda (sodium bicarbonate) gets hot, it produces a gas – carbon dioxide. This is the same gas that gives soda its fizz. In addition to carbon dioxide, the baking soda also creates water vapor and sodium carbonate. When the sugar (sucrose) is heated, it also creates carbon dioxide and water vapor. All that carbon dioxide has to go somewhere. It bubbles up and out of the mixture. However, as it does this, it pushes the carbonate up and out of the sand. That’s where the black snake(s) comes from! The snake is basically layer upon layer of that element we know and love – carbon!
