Sugar snake

Reagents

• Sodium hydrogen carbonate
• Sugar (sucrose)
• Hexamethylene-tetramine

Safety

• Put protective eyewear on.

• Conduct the experiment on the tray.

• Keep a bowl of water nearby during the experiment.

• Place the stove on the cork hot pot stand. Do not touch the stove after the experiment; wait until it gets cold.

FAQ and troubleshooting

Urotropine (solid fuel) lumped. How to measure it now?

Indeed, this reagent tends to lump when stored. We have foreseen this case and supplied a black ball-tipped rod in the set, which you may use to crush the lumped salt.

The solid fuel is too powdery and doesn’t clump up. What should I do?

Pour the solid fuel into a plastic cup and add 4 drops of water. Mix the wetted powder well and put it back into the mold.

Alternatively, you can also add 3 drops of liquid soap solution from the "Tin" set, which you received with "Chemistry of monsters" kit and perform the same operation.

Then proceed from step 4.

Can you eat or touch the snake?

You must never taste any of the chemicals or products of the reactions that you work with, even if, in theory, it should be safe to do so. Perhaps you got an unexpected product from your reaction, or perhaps the starting chemicals contained impurities. In any case tasting your experiment could be very dangerous.

It is for these reasons that eating in professional laboratories is strictly forbidden. Safety first!

After the "snake" has cooled you can touch it, but be careful, it may be hot. The carbon contained in the "snake" may smolder. The carbon form the "snake" will get onto your hands, so wash your hands after the experiment.

Step-by-step instructions

1. Take the solid fuel stove from the Starter kit. Place a piece of aluminum foil onto the stove. Caution! Use a cork hot pad to protect the tabletop.

2. Place the plastic ring in the center of the foil.

3. Pour out all the solid fuel inside the ring (2.5 g).

4. Take the press mold and push it down into the ring to make a crater with the solid fuel. Now, carefully remove the press mold.

5. Remove the plastic ring while slightly tapping onto it.

6. Pour in two level measuring spoons of sugar (2 g) into a vial with 0.5 g of sodium bicarbonate (NaHCO3) and close it with a cap.

7. Shake the vial for 10 seconds to mix sugar and sodium bicarbonate.

8. Now, pour out the mixture of sodium bicarbonate and sugar into the crater you made in solid fuel.

9. Ignite the solid fuel – and very soon, it will grow into a black “snake”!

Expected result

The solid fuel starts to burn. The mixture of sugar and baking soda in the flames will turn into a black "snake." If this experiment is done correctly, it is possible to grow a snake that is 15–50 cm long.

Disposal

Dispose of solid waste together with household garbage.

Scientific description

How does the snake form?

When sugar (C₁₂H₂₂O₁₁) burns (combusts), it turns into water vapor and carbon dioxide. However, complete combustion requires a good oxygen supply. Other complex processes take place at high temperatures, because the flow of oxygen to the inner parts of the pile of sugar is hindered. These processes include the decomposition of sugar to give carbon and water vapor. It is this decomposition to give carbon that gives us a carbon "snake".

Why do we add baking soda (NaHCO₃) to the sugar?

Baking soda decomposes when heated to release carbon dioxide (CO₂):

2NaHCO₃ → Na₂CO₃ + H₂O + CO₂

Baking soda is added to bread dough to make it rise, and it is the same for this experiment. The carbon dioxide and water vapor that is given off make the snake light and airy, which allows the snake to grow.

What is this "snake" made of?

The "snake" consists of mainly carbon that comes from the heated sugar, but which was not burnt in the flame. The carbon is what makes the "snake" black. There is also Na₂CO₃ in the snake, which results from the decomposition of the baking soda when heated.

What chemical reactions occur in the process of formation of the "snake"?

The three main reactions in this process are:

• Combustion of sugar (good oxygen supply available) to give carbon dioxide and water vapor:

С₁₂H₂₂O₁₁ + 12O₂ → 12CO₂ + 11H₂O

• Thermal decomposition of sugar to give carbon and water vapor:

С₁₂H₂₂O₁₁ → 12C + 11H₂O

• Thermal decomposition of baking soda to give sodium carbonate, carbon dioxide, and water vapor:

2NaHCO₃ → Na₂CO₃ + CO₂ + H₂O

That’s interesting!

What is sugar and where does it come from?

A sugar molecule consists of carbon (C), oxygen (O), and hydrogen (H) atoms. This is what a typical sugar, sucrose, looks like:

It is a little hard to make out the structure of sucrose from this image. Download the application MEL Chemistry on your smartphone or tablet so that you can twist and turn the sugar molecule and look at it from different sides to better understand its structure. Look for "sucrose" in the app.

The sucrose molecule is composed of two parts connected to each other by an oxygen atom (O). The two parts are glucose and fructose, which you may have heard of. Glucose and fructose are called simple sugars. Normal, household sugar is called a complex sugar, which means that the sugar molecules consist of several (two) simple sugars.

Here is what the simple sugars look like:

Glucose:

Fructose:

Sugars are important building blocks in plants. Plants produce simple sugars from water and carbon dioxide during photosynthesis. Simple sugars can be linked together to form small molecules, such as sucrose, or to form long chains. Starch and cellulose are examples of long-chain sugars that are made up of simple sugars, also known as polysaccharides. Plants use sugars as building materials and for nutrient storage.

The longer the sugar molecule, the more difficult it is for our bodies to digest it. Therefore we tend to love sweet things, which contain short, simple sugars. But your body was not designed to eat many simple sugars, and in nature they are rare. So be careful of the number of sweets you eat!