A How-To Guide: Fireworks-In-A-Jar Science Experiment

Singaporeans love a good light‑up. Few sights spark more excitement than the dazzling bursts over Marina Bay during National Day celebrations each 9 August. Whether you were perched on the Padang or watching from your living room window, those brilliant colours dancing across the night sky probably left you wide‑eyed and full of questions.

After the last echo of the fly‑past has faded, many children (and quite a few grown‑ups) start to wonder: is there a safe, fuss‑free way to recreate tiny fireworks at home? The answer is yes, and you don’t even need matches. This fireworks‑in‑a‑jar experiment lets you explore colour mixing, density, and a touch of chemistry using only everyday kitchen items. Gather some friends, roll up your sleeves, and let the sparks – well, droplets – fly!

Why try this experiment?

1. It’s safe and flame‑free.

2. It’s quick, about 10 minutes from start to finish.

3. It introduces key science ideas such as immiscible liquids, density differences, and how non‑living things shape the world around us.

4. It’s perfect for a rainy afternoon or as a fun extension to lessons from your primary science tuition in Singapore.

What you’ll need

Item	Quantity
A clear glass jar	1
Warm water	Fills ¾ of the jar
Cooking oil (any light oil works)	3–4 tbsp
Food colouring (various colours)	3–5 drops of each
A small bowl and fork	1 each
Old newspaper or tray	Optional

Tip: If you don’t have food colouring, try water‑based poster paint, but stir well so the droplets are small.

Step‑by‑step instructions

1. Fill the jar: Pour warm tap water until the jar is roughly three‑quarters full. Place it on your table where everyone can see.

2. Prepare the “shells”: In your small bowl, add the oil. Carefully drip different food‑colouring drops into the oil. The colouring will stay in neat blobs because it’s water‑based and doesn’t mix with oil.

3. Break up the blobs: Gently stir with the fork for just 5–10 seconds. You want the coloured droplets to become smaller but still separate. These are your mini firework charges.

4. Launch time: Slowly pour the coloured‑oil mixture onto the surface of the water. The oil will float, carrying the colour blobs like boats on a lake.

5. Watch the magic: Almost immediately, you’ll see tiny streaks of colour fall from the oil layer into the water below. As each droplet sinks, it unfurls like a blooming chrysanthemum – your very own underwater fireworks show!

6. Observe and discuss: Notice how some colours sink faster than others. Ask: Why does red reach the bottom first? How do the colours blend as they fall? Could we predict what might happen if we used cold water instead?

The science behind the sparkle

• Density differences

Oil is less dense than water, so it floats. Food colouring, however, is water‑based. When the coloured droplets finally break through the oil layer, they encounter denser water and sink, dispersing as they go. This movement creates those beautiful streaks.

• Immiscibility

Oil and water don’t mix because water molecules are polar (tiny magnets with positive and negative ends) while oil molecules are non‑polar. The two groups would rather keep to themselves, so the oil stays on top, acting like a gentle elevator that lowers the colouring into the water.

• Diffusion

Once the droplets enter the water, the colouring spreads out from areas of high concentration to low concentration, giving the soft, cloudy burst effect. Students exploring diffusion during a science tuition class in Singapore will recognise this pattern, just in brighter shades!

Extending the experiment

1. Temperature trials: Try cold water and hot (but not boiling) water. Does diffusion speed change? Record times and plot a simple bar chart.

2. Saltwater surprise: Dissolve two tablespoons of salt into the warm water first. Salt increases water’s density. Will your “fireworks” sink more slowly?

3. Layered fireworks: Use a tall, thin vase. Pour in honey, coloured washing‑up liquid, water, vegetable oil, and even rubbing alcohol in separate layers. Then add the colouring oil mix on top. Which layer does each droplet stop at? This mini‑stratified tower is a favourite demonstration during holiday workshops.

4. National Day theme: Only use red and white colouring to mirror the Singapore flag. Snap photos and create a collage for your science journal.

Linking classroom learning

Teachers often emphasise hands‑on activities to make abstract ideas stick. This experiment blends topics such as properties of materials, changes of state, and interactions, all part of Singapore’s primary science syllabus. If you’re revising for an upcoming assessment, pair this demonstration with related questions:

• “Explain why the oil floats on the water.”

• “Predict what would happen if the food colouring were mixed straight into the water without oil.”

• “How might this model help us understand real fireworks in the sky?”

You’ll sharpen observation skills and practise writing concise answers, which is handy for those open‑ended exam questions!

Conclusion

The fireworks‑in‑a‑jar experiment proves that learning science can be spectacular, safe, and wonderfully simple. You’ve explored density, immiscibility, and diffusion, all while creating a miniature celebration worthy of National Day. Ready to dig deeper? Heuristics Science offers science tuition in Singapore using our specialised TCR Answering Technique, guided practice, and practical applications to help you shine bright in every topic.