Mystery Baloon Materials: small baloon funnel 10 oz soda bottle 1 Tbsp baking soda 1/2 c vinegar Method Clean and dry the bottle well. Funnel baking soda into bottle/ Funnle vinegar into balloon. Attach the baloon snuggly to the bottle neck. Gently squeeze the vinegar down into the bottle. The mixture will sizzle and pop and the baloon will inflate as carbon dioxide gass is produced. .