--- title: "Baking soda and vinegar experiment: the fizzing volcano" description: "Why baking soda (bicarbonate of soda) and vinegar fizz, how to make a coloured volcano with an adult, and how the fizz looks in Extreme Drawing." source_name: "Game Tailors" source_url: "https://extreemtekenen.nl/en/experiments/baking-soda-and-vinegar/" site_home: "https://extreemtekenen.nl/" source_description: "The drawing app where the paper is real. No ads, no accounts, no data collected." locale: "en" legal: - "Game Tailors · Schieweg 15Y-40, 2627 AN Delft (NL)" - "KvK 92437702 · VAT NL866044474B01" - "info@gametailors.com · +31 6 4227 5919" copyright: "© 2026 Game Tailors" published_at: "2026-10-24T00:47:11.321Z" modified_at: "2026-10-24T05:04:52.510Z" --- # Baking soda and vinegar experiment: the fizzing volcano ## Make a fizz that runs like lava Vinegar is an acid and baking soda is a base. When they meet, they react and make carbon dioxide gas, so the mixture foams up, overflows like lava and then goes flat once one of them is used up. [Play in your browser]()[Do it for real](<#for-real>) - Ages 4\+ - 15 minutes - With an adult ![Painted illustration of the painter pouring red vinegar onto a heap of baking soda on a tray, which fizzes up into pink foam.]() ## Quick facts Age 4 to 10 \(little ones with help\) Time About 15 minutes Mess Medium: do it on a tray Adult needed Yes, to pour and to keep vinegar out of eyes You need Baking soda, vinegar, food colouring \(a few pence/cents\) On screen / for real Both ## In Extreme Drawing Open the **Science** tab. Shake the **Baking soda** sieve to dust a white heap onto the paper, then pick **Vinegar** and let drops fall on it. The heap fizzes up into a foam that rises, runs downhill like lava and then collapses, with a hiss. The white powder is really used up as it fizzes, so a big heap keeps going longer than a thin dusting. The foam takes the colour of whatever dye is in the paper under it. Choose **Red vinegar**, **Blue vinegar** or **Yellow vinegar**, or drip **Food colouring** first and dust the soda over it, and every patch fizzes in its own colour. The acid soaks along through wet paper and through the fizz itself, so one drop can set off a whole heap. Things to try: - Any acid fizzes, not just vinegar: put a lemon slice \(Kitchen\) or lemon-juice secret ink on the soda. Vinegar fizzes harder than juice. - Paint red cabbage juice first: it turns pink where the vinegar lands and green where the soda lies. - Dust soda in a pattern with the sieve, then drip vinegar along it and watch the fizz travel down the line. [Play in your browser]() ![Painted illustration of the painter, goggles on his beret, studying a bottle foaming over in stripes, with red cabbage juice in pink and green glasses and fizzing baking soda.]() ## Do it for real: a coloured volcano **You need** - A tray, baking dish or the kitchen sink - A small cup, jar or plastic bottle \(open at the top\) - Play dough, modelling clay or damp sand for the volcano \(optional\) - 2 to 3 tablespoons of baking soda \(UK: bicarbonate of soda\) - About 100 ml \(half a cup\) of white vinegar - Food colouring - A squirt of washing-up liquid \(dish soap\) for extra foam - Goggles or sunglasses if you have them [Why you never mix bleach and vinegar]() 1. Set up somewhere wipeablePut the tray on a table you can wipe, or work outside. Put on goggles if you have them. 2. Build the volcanoStand the cup in the middle of the tray. Press play dough or clay round it into a mountain, leaving the top of the cup open. \(A plain cup works too.\) 3. Load the sodaSpoon 2 tablespoons of baking soda into the cup. Add a few drops of food colouring and a small squirt of washing-up liquid. 4. PredictAsk: how high will it go? Will it fizz for a long time or a short time? What colour will the lava be? 5. Pour the vinegarThe grown-up pours the vinegar in, all at once for a big eruption or a little at a time for a slow one. Step back and watch. 6. Find out what ran outWhen it stops, add a splash more vinegar. If it fizzes again, there was soda left over. If not, add a spoon of soda instead: now the vinegar was left over. 7. Try the Extreme Drawing waySprinkle a thin layer of soda over the tray and drip coloured vinegar on it with a spoon or pipette. Every drop fizzes in its own colour. Safety and clean-up - Vinegar stings eyes. Keep faces back from the cup, and rinse with plenty of water if any splashes in an eye. - Never put a lid or cork on a bottle or jar with the mixture inside: the gas builds up pressure. - Don't drink it, and keep the bottles away from little ones afterwards. - Never mix vinegar with bleach: together they make poisonous chlorine gas, not a fizz. - Clean-up is easy: what's left is salty water. Rinse it down the sink. Food colouring can stain clothes and wooden tables. ![Painted illustration of the painter pouring purple red cabbage juice into a row of glasses that go from pink through purple and blue to green, with a lemon and baking soda.]() ## Why it works **For kids:** vinegar is an acid and baking soda is a base. When they touch, they swap parts and make something new: a gas called carbon dioxide, the same gas that makes the bubbles in fizzy drinks. The gas makes bubbles, and the bubbles make the foam. **For grown-ups:** sodium bicarbonate \(NaHCO₃\) reacts with the acetic acid in vinegar \(CH₃COOH\). The carbonic acid that forms breaks down straight away into water and carbon dioxide \(CO₂\), leaving sodium acetate dissolved in the water: NaHCO₃ \+ CH₃COOH → CH₃COONa \+ H₂O \+ CO₂. The washing-up liquid traps the gas in longer-lasting bubbles. The fizz stops when one reactant runs out \(the limiting reactant\), which is what step 6 tests. A new substance forms, so this is an irreversible change. The reaction also takes in a little heat: a cup of it feels slightly cooler. In the game every spot of paper has its own acidity, and anything acidic fizzes with soda by the same rule. Nothing in the code pairs "vinegar" with "soda" by name, which is why lemon works too. ## Try next: predict, then test ### Vinegar or lemon juice? Which fizzes harder? Test both on the same amount of soda, then check on screen. ### More soda or more vinegar? Which one makes the eruption bigger, and which one makes it last longer? ### Warm or cold vinegar? Does warm vinegar \(from the tap, not boiling\) fizz faster than vinegar from the fridge? ### Does it get colder? Hold the cup while it fizzes. Does it feel warmer or cooler than before? ## For teachers This experiment fits KS2 Year 5 "properties and changes of materials", where the action of acid on bicarbonate of soda is a named example of an irreversible change, and NGSS 5-PS1-4 \(mixing two substances can make a new one\). Show the fizz on the whiteboard first, ask the class to predict, then do the volcano on a tray. [Reversible and irreversible changes lesson]() ## Questions about baking soda and vinegar Is baking soda the same as bicarbonate of soda? Yes. Baking soda \(US\) and bicarbonate of soda or bicarb \(UK, Ireland, Australia\) are both sodium bicarbonate. Baking powder is different: it already contains an acid, so it fizzes with plain water and gives a weaker volcano with vinegar. What gas do baking soda and vinegar make? Carbon dioxide. It is heavier than air, so it pools low around the volcano before it drifts away. Why does the fizzing stop? One of the two has been used up. Add more vinegar: if it fizzes again, there was soda left; if not, the soda ran out first. Is the baking soda and vinegar experiment safe for kids? Yes, with an adult: both are kitchen ingredients. Keep vinegar out of eyes, never seal the mixture in a closed bottle, and never mix vinegar with bleach. Can I make a volcano without vinegar? Yes, with any kitchen acid such as lemon juice. It fizzes a bit more gently than vinegar. ## More fizz and colour ![Painted illustration of the painter pouring purple red cabbage juice into a row of glasses that go from pink through purple and blue to green, with a lemon and baking soda.]() ### [Red cabbage pH indicator]() Find out which kitchen liquids are acids and which are bases, by colour. ![Painted illustration of a bottle on a tray pouring out a fat foam snake in pink, yellow, blue and white stripes, the painter in goggles leaning back, amazed.]() ### [Elephant toothpaste]() A giant snake of foam, and the safe household version to do with an adult. ![Painted illustration of the painter in oven gloves sniffing a golden loaf, with a ball of dough, a rolling pin, a bowl of yeast and a pretzel.]() ### [Bread and yeast]() Soda bread rises with this same fizz, trapped inside the dough. ## Fizz it on screen first Dust the soda, pick a coloured vinegar and watch the lava run. Then build the real one on a tray. [Play in your browser]()[All experiments]()