Why does the raisin sink and float when put in a soft drink?

Answer 1

The raisins are actually denser than the soda, making them sink, but the carbon dioxide (CO2) bubbles in a fizzy drink are drawn to the surface of a raisin. When enough bubbles have coagulated, it raises the raisin higher because of the increased buoyancy, allowing it to float to the surface. Once the raisin reaches the surface, the bubbles pop and the carbon dioxide is released into the air, thus giving the raisin a "dancing" motion. The released carbon dioxide causes the raisin to sink again so it can collect more bubbles. The bubbles act as a life vest that vanishes when it reaches the surface.

The rising and falling of the raisins stops when most of the carbon dioxide has escaped from the soda. Sometimes, the raisin absorbs too much water and it sinks to the bottom. This experiment also works with baking soda and vinegar. Vinegar has acetic acid, which reacts with the baking soda, which is a base. The compounds for baking soda and vinegar (acetic acid) are NaHCO3+CH3COOH. This "dancing" movement also works with many different objects, such as macaroni or corn.

For more information, visit Steve Spangler's "The Bubble Lifter".

Answer 2

When you put a raisin in a soft drink, gas bubbles gather on the rough surface of the raisin, making it buoyant and causing it to float. As the gas bubbles escape, the raisin becomes denser and sinks. This process of floating and sinking continues as more bubbles form and escape.

Answer 3

Most drinks are preserved using gases like carbon dioxide. When closed the density of the drink is smaller due to the small weight of gases compared to their bigger volumes.

Answer 4

No it is heavier than the water