Halloween Science: Smoking and Oozing Pumpkins

This is a fun and easy science activity to utilize the properties of dry ice to producing smoking and oozing pumpkins.

You will need:

Carved pumpkin, small dish, dry ice (solid carbon dioxide, can be purchased at Meijer), warm water, bubble solution, food coloring

Now try this:

For smoking pumpkin:

1. insert warm water in small dish into the center of a carved pumpkin.

2. Place a small piece of dry ice into the water and place top onto the pumpkin. Observe the "smoke" coming out of the pumpkin.

For Oozing pumpkins:

1. Insert warm bubble solution in small dish into the center of the carved pumpkin

2. Place a few pieces of dry ice into the water and place the top onto the pumpkin. Observe the "oozing" pumpkin.

3. For a unique affect, use food coloring in the bubble solution.

What is happening?

Dry ice is solid carbon dioxide that is at a temperature of -78.5^OC (109.3^OF). When the temperature increases, the solid carbon dioxide does a phase change to a gas. This is a unique substance that does a phase change from a solid to a gas without going through it's liquid phase. This process is called sublimation. When placed in water solid carbon dioxide takes water into the atmosphere as water vapor, this is what makes the pumpkin look like it is smoking. The gas also gets trapped into a bubble when placed in bubble solution. The carbon dioxide-water vapor mixture is also heavier than air so it falls to the ground when formed.