Instant Freeze Water – Bottle Slam
Sharply knock a bottle of supercooled liquid water on the table and it instantly turns to slushy ice before your eyes.
Instant-Freeze Water Experiment (the Bottle Slam Science Experiment)
In our instant-freeze water experiment, you’ll see a bottle of ice form like magic! When you sharply knock a supercooled bottle of water onto the table, it will instantly turn to slushy ice — right before your eyes. This bottle slam instant-ice experiment demonstrates the concept of the “freezing point depression,” in which a liquid’s freezing point is lowered (or depressed) by adding another compound to it.
A Super-Cool Experiment: Instant Freeze Water Science Experiment
Have you ever put a plastic bottle of soda pop or water into the freezer for a few minutes to get it ice cold? You may have noticed that it is still a liquid when you take it out of the freezer; however, the second you twist that cap, the liquid instantly turns to slush! The process is amazing to watch; however, it is hard to repeat.
Our instant-freeze water science experiment is a great illustration of how supercooled liquids can defy freezing — even when those temperatures plummet well below their freezing points. You will just need a few easy household ingredients for this cool science demo experiment: ice, salt and several unopened plastic bottles of purified water. It’s cool — like, below-the-freezing-point cool!
First Things First
If the instant freeze works on your very first attempt, go buy a lottery ticket! Patience is the key with this instant-freeze water experiment. You have to be patient and understand that all of the measurements of time, ice, water and rock salt are summaries of what has worked for others. Shoot a video of every attempt you make and document your hits and misses; plan on several misses, too. When the ice crystals do begin to form in the water as planned, expect to hear lots of spontaneous screams and cheers coming from – you! It really is cool. Just remember: NO glass bottles!
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- CAUTION: Do NOT use glass bottles!
- Water: bottled, purified, or distilled (several bottles, refrigerated)
- Large, deep bowl or container
- Crushed ice
- Rock salt
- Adult supervision
Nearly fill the container with ice.
Shove two refrigerated, plastic water bottles deeply into the ice. Keep them close to the center of the bowl but keep each surrounded by and buried in ice as much as possible.
Scatter a generous amount of rock salt all over the surface of the ice.
Insert the thermometer into the ice between the bottles. Monitor the temperature. Over the next half-hour, the temperature will fall slowly. Add ice and salt to the container as needed to keep the bottles buried in it. Watch that thermometer!
The temperature in the bowl needs to drop to 17℉ (-8℃). If the water gets too much colder, it may freeze prematurely.
After the water has been this cold for 10 minutes (and is still a liquid), gently remove a bottle from the ice/salt mixture. Strike the bottle sharply against the table. Ice crystals may immediately form near the top of the bottle and quickly move down through the liquid. Carefully remove the second bottle and twist open the cap. The same instant freezing will likely occur from the top down.
How Does It Work
In this experiment, you used salt and ice to drop the temperature in the chilled mixture below the normal freezing point of water. This is called the “freezing point depression.” This very cold salt water can be used to cool other water and soda samples below their normal freezing points in order to discover which of them can be supercooled. You might also discover which samples freeze at their normal freezing points — no matter what.
The process of freezing water is actually very orderly: molecules come together in a very orderly way and form a crystalline structure. Because of this, frozen water molecules have less energy than liquid water molecules. To transform from liquid water to solid water, the molecules have to lose heat energy. In other words, as supercooled water freezes when you tap it or open it, it also warms up the rest of the water. This heating may allow only ten or twenty percent of the water to freeze; that accounts for slush being inside the bottle (instead of it being in one solid chunk). The formation of ice crystals happens very quickly; however, heat flows slowly in water.
When water is cooled to its freezing point, ice crystals can begin to collect in the water. Like snowflakes, these crystals need something on which to grow: they use microscopic impurities in the water or on the bottle to do just that. If you work with really pure water and cool it slowly to produce supercooled water as a liquid, there’s different outcome. When an impurity (like an ice crystal) is added to this supercooled pure water, it speeds up the crystallization process even more. The water instantly freezes solid with no slush in it anywhere. This is called “snap freezing.”
If you supercool soda water or soda pop, there are some other factors to consider. When soda pop is produced, large quantities of additives (like sugar, colors, flavorings) and carbon dioxide (CO2) are pumped into water. These additives are called “solutes.” When solutes are added to a liquid such as water (the solvent), the freezing point of the water drops. By lowering the freezing point, soda has to reach a much colder temperature than plain water to freeze. The carbon dioxide gas in the soda is maintained — only as long as the bottle is kept sealed. When the bottle is opened and you hear that “whoosh” of gas and foam rushing out of the bottle, the concentration of solutes in the water quickly goes down. The freezing point goes up and, without all those solutes, the soda freezes very quickly. Of course, all those bubbles provide places for the ice crystals to form, too. You can test this by tapping a supercooled bottle of soda pop without opening it. Bubbles will form after the tap and freezing will likely occur.
Steve Spangler Science Experiments
If you thought this instant-freeze water experiment was pretty cool, then you’ll really like our other hands-on science experiments for kids. Our easy kids’ science experiments are great ways to demonstrate the fascinating concepts of science at home, in the classroom or as a fun STEM club activity. Check out our library of science experiments with that Steve Spangler Science WOW factor (like this one!), including food science experiments, energy experiments, table tricks experiments and weather experiments. Can’t get enough of Steve Spangler Science? Join our Steve Spangler Science Club — our monthly science-kit-of-the-month club that will keep those entertaining, relevant science lessons coming directly to your door. They’re great for after-school activities, holiday break activities and exciting weekend family time fun activities that will keep kids asking questions about the world around them!