Have your students ever explored the phenomenon of sublimation? If you are ready to take your lab experience to the next level, keep reading!
Every year I look forward to the Sublimation Stations lab with dry ice!
There are so many ways to integrate it into the curriculum! It’s a fun way to extend a matter unit. This station inquiry is also a great way for students to practice writing a hypothesis and making observations!
The end of October is always fun for this lab! It is a great way to “celebrate” Halloween in middle school without candy, costumes or a party. This lab IS THE PARTY!
Dry Ice Demonstration
Sublimation is the process of changing from the state of a solid to a gas. An awesome way to introduce sublimation is with the candle demo.
Pour several pieces of dry ice into a beaker. Show the students a lit candle. Ask the students to make a hypothesis about what will happen when you “pour” the dry ice onto the candle.
As your students watch the demo, they will observe that the flame will go out. They will also observe that the vapor coming off of the cup goes down, unlike hot steam, which rises. This is due to the temperature difference and the density of the CO2 gas which is heavier than air. Also, it does not provide oxygen for combustion.
After discussing this dry ice experiment with your class, I like to let them loose with the sublimation stations.
Dry Ice Inquiry Based Stations for Kids
I have created a set of six inquiry based dry ice stations for students to explore. Each station uses commonly found household objects (such as a popsicle stick, balloon, and penny) to investigate dry ice.
These dry ice experiments are a great way for your students to practice following simple instructions, making a hypothesis, and writing observations.
I also encourage my students to write an explanation for “why” they the dry ice is behaving that way to encourage them to think about the “science” behind the fun!
Early finishers love to design their own dry ice experiment – teacher approved of course!
Dry Ice Safety Precautions
- Use tongs to handle dry ice.
- Do NOT hold the dry ice in your hand for a long period of time. It will not hurt you to touch it for a second of two, but if you try to hold it, it can freeze your skin and feel like a burn.
- Never put dry ice into a closed glass container.
- Do NOT put dry ice into your mouth.
- Use appropriate eyewear.
Tips for purchasing and storing dry ice:
- It’s all in the planning! Since dry ice “melts” over time, it’s best to get it as close as you can to when you will be using it. Store the dry ice in an insulated cooler. Be sure to keep the lid on top until you need to remove pieces for the activity. If there is space in the cooler, you may want to pack it with newspapers to insulate it and help it last longer.
- Slab vs Pellets – Pellets can be easier to handle for activities, but tend to “disappear” faster if you don’t use it quickly enough.
- Often you can find dry ice at your local Kroger. Walmart and Costco often have dry ice as well – it’s best to call ahead of time and pick it up the morning you are using it.
- Often fundraisers (such as cookie dough) are shipped in dry ice. Our science department fights over every shipment – it’s free fun!
Sublimation Stations Inquiry Lab
- Dry Ice Background Information
- Materials list (household items)
- Dry Ice Demo Directions
- Explanation of each phenomena for teachers
- 6 directed stations
- 1 design your own experiment station
- Student handout
- Black and white version for ease of printing