1. Withings Body Cardio. Measures: Full-body composition, body fat, water percentage, muscle and bone mass. Perfect for: Fitness and health fiends. Selling points: Accuracy; compatible with more third-party apps and devices than the other smart scales we tested. Drawbacks: None.
In this reaction, baking soda acts as a base, and takes a proton from vinegar, which is an acid. The reaction releases gas because when the baking soda receives the proton, it transforms into water and carbon dioxide.
When sodium bicarbonate and vinegar mix, they react with each other and one of the things that is made is carbon dioxide gas. The reaction needs heat to make it happen, so it takes heat from its surroundings, leaving the bottle feeling cold. The gas couldn't escape because it was trapped by the balloon.