That bag didn't just inflate. It ran a chemical reaction, captured the product, and exploded from the inside.

When baking soda and vinegar meet, they trigger an acid-base reaction. Vinegar is a weak acid. Baking soda is a base. The moment they combine, they react to produce carbon dioxide gas — CO₂ — along with water and a dissolved salt called sodium acetate. The fizzing you see is the CO₂ escaping as fast as it forms.

But in your bag, the CO₂ has nowhere to go.

The gas molecules spread out and push against every surface — that's pressure. The more CO₂ that forms, the higher the pressure climbs. The bag stretches because it's made of polyethylene — a polymer whose long chain-like molecules slide and deform rather than snap immediately (the same property that lets [The Magic Skewer] seal itself around a skewer without leaking). But there's a limit.

The moment the pressure exceeds what the bag can hold, the seals give way — and the bag bursts.

The CO₂ your reaction produced is the same gas in every carbonated drink, every fire extinguisher, and every Mentos geyser. In [The Invisible Fire Extinguisher], you'll use CO₂ from the exact same reaction to smother a flame — same gas, completely different result.

Curiosity spark: The reaction between baking soda and vinegar produces CO₂ quickly — but what do you think would control how fast the bag inflates? Is it the amount of baking soda, the amount of vinegar, or the temperature of the vinegar?

Find out in The Crazy Scientist Lab.