Dry Ice Experiments and Keeping Ice Cream Cold While Camping Overnight

If you’ve ever brought ice cream on a picnic or camping trip, you know it can melt even when packed in ice. That’s because it melts at a slightly lower temperature than ice. One solution is to add salt to the ice to lower its melting temperature. Another is to use dry ice, which is frozen CO2. Unlike regular ice, dry ice doesn’t turn into liquid when it warms up—it changes directly into gas at -78°C (-109°F).

This project will use dry ice to keep ice cream frozen and explore some fun CO2 experiments.

Dry Ice (Frozen CO2)

Ice Cream

2 Kg of dry ice was purchased in a polystyrene container (with a lose fitting lid so gas can escape). As the dry ice did not take up all the room, scrunched up newspaper was used to take up the extra space. This assists in keeping the dry ice frozen as long as possible. A 2-liter tub of ice cream was purchase and placed next to the dry ice. At the camping ground the container was placed in the shade away from direct sunshine to assist with its longevity. The dry ice lasted longer than expected and there was still a little left after 36 hours of being in the polystyrene container - autumn temperatures probably helped with this.

As an experiment, a lump of dry ice was added to a bowl of hot water. This resulted in the bowl 'smoking' for a while and looked quite spectacular. Leather gloves were worn while handling the dry ice for safely.

Placing dry ice on a flat bowl with a serving bowl on top can create a cool effect when water is added. The second time handling dry ice, regular gloves were used, which seemed to protect the hands from frostbite.

Three beers and a bottle of white wine were placed in the container near the dry ice. They were removed after 6 hours. The beer had cooled to -4c and the wine was partly frozen. Next time they would be place further away from the dry ice in the container, so they don't become so cold.

As an experiment, a lump of dry ice was placed directly into a cup of soda water. It cooled from 14c to 1c within 2 minutes. Some of the beverage was lost at the start when the beverage bubbling over. It is important not to drink dry ice to prevent physical harm.

A safer way is to place dry ice in a tea soaker and dangle this into the liquid.

A lump of dry ice was added into a latex glove and the end sealed. The glove inflated and after about 15 minutes popped.

On another summer trip, dry ice was added to a couple of large balloons, with warm to hot water poured in to help the dry ice sublimate. To do this, a balloon was stretched over the top of a beer can which had both ends removed, dry ice was poured in, followed by hot water. Once the balloon was tied off, it began to expand. Placing it in a large bowl of hot water helps keep the dry ice sublimating quickly.

While the balloon expands, you can play a game called “pass the balloon” to see who’s left holding it when it pops.

I had read that if dry ice was place in water and detergent and a piece of towel dragged across the top a large bubble would be created. I tried this experiment, but it resulted in a bowl of bubbles without a large one forming.

A spoon was placed against a large piece of dry ice. It hummed in a similar way to the 'Everything Is OK! Alarm'

How did the dry ice go at keeping the ice cream cold? When the ice cream was taken out it was rock hard. This was due to having the dry ice directly around it. The ice cream was then placed back into the container but away from the dry ice. When it was checked on in the morning it was like ice cream from the freezer.

I placed some water in a can and placed it next to the dry ice overnight. It had frozen solid in the morning. Another use of dry ice is to keep HO2 ice frozen longer. As dry ice is a lot cold than ice made from water it will keep the ice completely frozen until all the dry ice has sublimated (turned to gas). This will result in the ice in a cooler lasting longer than being just by itself, just remember to keep the lid lose so the gas from the sublimating solid CO2 can escape and have good ventilation.

Balancing a beer can has nothing to do with dry ice or ice cream but it's kind of cool. After drinking about 3/4's of a can of beer, you may be able to balance it on an edge.