Sugar makes any dessert an extra scrumptious treat, but what happens when you add a bit of science fun to the sweet tasting substance and start heating sugar? Be a chemist for a day and study the simple reaction between sugar and heat. It's an experiment your sweet tooth (and your sweet nose!) will love.
How does sugar react to heat?
- Aluminum foil
- Measuring spoons
- Large candle
- Magnifying glass
- Metal dish
- Use a ruler and a pen to measure and mark a three inch squre on the aluminum foil.
- Cut the square out.
- Stick your thumb in the middle of the square and use your other hand to lift the sides of the foil around your thumb, creating a miniature boat shape.
- Measure 1/4 teaspoon of sugar.
- Put the sugar in the foil boat.
- Study the sugar with your magnifying glass. Can you see each individual sugar piece?
- What do you think will happen when you heat the sugar? Write your guess, or hypothesis, in your notebook.
- Have a grown-up use matches to light the candle.
- Put the metal dish next to the candle.
- Using the tongs, hold the foil boat just above the flame.
- Slowly count to ten as you observe what happens to the sugar. Don't just use your your eyes -- use your nose to note how the sugar smells.
- Remove the foil boat and blow out the candle.
- Set the heated sugar on the metal dish.
- Use your magnifying glass to study the heated sugar.
- Did the sugar do what you expected?
The sugar should have melted down to a liquid form and turned a light brown color. Once the sugar had been heating for awhile, it should have turned black and started producing wisps of smoke. Once you transferred the sugar from the flame to the metal dish, the sugar would be blackish brown, solid and surrounded by black soot.
Sugar is made of carbon, hydrogen and oxygen atoms. When heated over a candle, these elements react with the fire to turn into a liquid. The heat causes the sugar's atoms to combine with the oxygen in the air, forming new groups of atoms. Energy is released in this chemical reaction in the form of smoke and black soot.
We can't usually tell the chemical composition, or what exact elements make up a substance, just by using our eyes. Did you know, for example, that sugar contained carbon, hydrogen and oxygen? Scientists can guess what will happen when your heat a substance if they know its chemical composition.
What other substances can you test? Have a grown-up help you conduct this same experiment, but with salt. Do you think salt will react the same way as sugar does? Keep guessing and testing different substances and try to see if the chemical composition explains the reaction. You're on your way to becoming a real scientist!