How to Melt Ice Using Kosher, Rock & Iodized Salt

Simple table salt can melt ice.

Whether kosher, rock or iodized, all salt is made primarily of sodium chloride. When sodium chloride comes in contact with ice, it works as a substance that dissolves ice, known as a solute. The sodium chloride molecules disrupt the bond between the water molecules within the ice, reducing the freezing temperature and causing the ice to melt. When the salt is removed, the water will refreeze, if temperature conditions are appropriate. A simple experiment with an ice cube, some iodized table salt and a thread can demonstrate how salt melts ice.

Things You'll Need

• Glass filled with cold water
• Ice cube
• Cotton thread, 12 inches in length
• Iodized salt

Instructions

1. Place the ice cube in the glass filled with cold water. Immediately sprinkle some salt on top of the ice cube. Observe the salt melting the ice cube.

2. Place the thread across the ice cube, then immediately lift up both sides of the thread. The thread should come up off the ice cube easily because the salt keeps the ice melted.

3. Place the thread across the ice cube again and leave it there for 1 to 2 minutes. During this time, the water in the glass will dilute the salt on the ice cube. This raises the freezing temperature of the water on top of the ice cube.

4. Lift both sides of the thread up. The ice on top of the ice cube will have refrozen around the thread, allowing you to lift the ice cube from the glass with the thread.

References

• University of Regina Center for Mathematics, Science and Technology Education: Lift an Ice Cube With Salt
• Frostburg State University: "Why Does Salt Melt Ice?"; Fred Senese; 2010