Hooked on Science: Exploding sandwich bag

Materials

• Baking soda
• Vinegar
• Paper towel
• Sandwich bag

Instructions

• Step 1: Tear a paper towel into four equal pieces. Using one of the pieces, pour two tablespoons of baking soda into the center of the paper-towel square. Describe the baking soda by its observable properties.
• Step 2: Fold the square into a smaller square so the baking soda stays inside.
• Step 3: Fill the sandwich bag one-fourth of the way with vinegar. Describe the vinegar by its observable properties.
• Step 4: Drop the paper towel into the sandwich bag. Hold the bag over the trash can, close it and observe. Did mixing the two substances result in a new substance?

Explanation

When the paper-towel square containing the baking soda is placed into the bag containing the vinegar, a chemical reaction happens, which creates carbon-dioxide gas. The carbon-dioxide gas fills the bag, causing the bag to expand and eventually pop.