Overview:
In this experiment, students will learn about temperature and ice. They will observe how salt affects the freezing point of water. Students will fish for ice.
Time:
5 minutes
Lesson Materials:
*You can use the document in the link below to either: tailor the experiment to your needs or to have a printable version of this lesson plan*
The plan is editable and printable. Copy the Google Doc in your own drive and make edits or you can just print.
Ice Fishing Lesson Video:
Learning Objectives:
- Identify what the freezing temperature of water is
- Observe the effect salt has on freezing temperature
- Explain how ice stays on the string
- Build an ice necklace/ fish for ice.
Materials Needed:
- Small cup, bowl, or an ice cube tray
- Glass of water
- String
- Salt
- Small stick (optional)
Experimental Methods:
- Fill the cup with water and place it into the freezer
Alternatively, Use ice cubes from the freezer.
- With the water frozen into ice, remove it from the cup
- Place the ice in the glass or bowl of water
- Place the string over the ice cubes and sprinkle salt over where the string touches the ice
- Observe how the ice melts and refreezes
- Carefully lift the string out of the water with the ice cubes attached to it
Optional: Tie one end of the string to a small stick so it is as if you caught a fish!
Questions to Think About:
- Why does the ice melt with the salt?
- Why does the ice refreeze over the string?
- Would other things such as sugar work over salt?
Chemistry:
The freezing temperature of water is 32 degrees Fahrenheit. When added to water, salt lowers the water’s freezing temperature. This means that the water must be colder than 32 degrees for it to freeze. How much colder depends on how much salt is on the ice. So, the salt lowers the freezing temperature which causes the ice to melt. The string can then sink into the water. The ice melting also dilutes the solution of water and salt, making the freezing temperature go back up. The ice then refreezes with the string inside of it.
Society:
In areas where snow is an issue, trucks will spray salt on the roads to protect drivers from slippery conditions. As mentioned before, salt lowers the freezing temperature of water, so this is a cheap and easy solution to keep the roads safe when it’s cold out.
Logistics:
STEAM Subjects:
Science (Chemistry) and Art
Science Vocabulary:
Freezing temperature and melting temperature
References:
Littlebins, Winter Science Ideas for Fun Winter Science Theme Lesson Plans says:, & Weekend Links – Beachwood Schoolhouse says:. (2019, January 10). Ice Fishing Winter Science Project: Fishing for Ice! Retrieved October 14, 2020, from https://littlebinsforlittlehands.com/ice-fishing-winter-science/
Pollock, J. (2019, February 12). Salt Doesn’t Melt Ice-Here’s How It Makes Winter Streets Safer. Retrieved October 14, 2020, from https://www.scientificamerican.com/article/salt-doesnt-melt-ice-heres-how-it-makes-winter-streets-safer/
