What happens after a raisin is dropped in corn syrup?

When a raisin is dropped in corn syrup, it undergoes several physicochemical changes due to differences in their respective densities and the properties of corn syrup. Here's what happens:

1. Initial Sinking:

Initially, the raisin will sink to the bottom of the corn syrup. This is because raisins are denser than corn syrup at room temperature.

2. Absorption of Corn Syrup:

Once in the corn syrup, the raisin starts absorbing it due to the osmotic process. Corn syrup is a concentrated sugar solution, and osmosis occurs when a semipermeable membrane separates two solutions of different concentrations. In this case, the semipermeable membrane would be the skin of the raisin.

3. Swelling and Expansion:

As the raisin absorbs corn syrup, it swells and begins to expand in size. The influx of sugar molecules into the raisin leads to increased internal pressure, causing it to puff up.

4. Change in Density:

As the raisin expands and absorbs more corn syrup, its overall density decreases. This means that the raisin becomes less dense than the surrounding corn syrup.

5. Buoyancy and Floatation:

Once the raisin becomes less dense than the corn syrup, the principle of buoyancy comes into play. Buoyancy is the upward force exerted by a fluid that counteracts the weight of an object immersed in it. In this case, the corn syrup exerts an upward force on the raisin, causing it to float to the surface.

6. Continued Swelling and Floating:

As the raisin continues to absorb corn syrup, it gradually rises through the syrup until it reaches the top, where it floats with its upper surface exposed to the air.

7. Equilibrium Reached:

Eventually, the raisin will reach an equilibrium where its internal sugar concentration matches that of the corn syrup. At this point, the rate of water and sugar movement between the raisin and the corn syrup will balance out, maintaining a stable state.

Please note that the speed at which these changes occur may vary depending on the initial state of the raisin and the temperature and density of the corn syrup.