Houston summers are HOT! And while cooling off at the Children’s Museum of Houston is a great thing to do, another delicious way to cool off is to enjoy some ice cream! When making homemade ice cream, we most often use ice and rock salt to freeze the ice cream. But that confuses a lot of people – after all, salt melts ice, so how can the combination of ice and rock salt get cold enought to freeze the ice cream. Well, let’s get to that after making the ice cream, so you have something to snack on while reading…
What You Need:
- Flavored, non-dairy coffee creamers (you choose the flavor)
- Rock Salt
- Plastic containers (I used some containers in which I get take-out soup – about a quart size)
- Gloves or a dish towel
What To Do:
- Fill the container ¾ full with ice.
- Add ½ cup of rock salt.
- Add in 5 or so non-dairy coffee creamers.
- Put on gloves, seal container, and shake for 5 minutes.
- When done, peel open the creamers and enjoy!
Pure water freezes at 32°F or 0°C. But, if you add salt to it, you get saltwater, which freezes at a lower temperature, as low as -6°F or -21.1°C. This lowering of the temperature where water freezes is called freezing point depression.
As ice melts, it takes heat energy from the area around it. So, when the ice absorbs heat energy from the saltwater, the temperature of the saltwater goes down. However, because of freezing point depression, the saltwater won’t refreeze. This means that even though the temperature of the saltwater drops below 32°F or 0°C, the ice will keep melting. So, the more the ice melts, the more heat energy is absorbed, and the colder the saltwater gets. And we can use that low temperature to freeze the ice cream!
Special thanks to our friends at Region’s Bank for making our O Wow Moments possible!