Posts: 1
Joined: Mon Jan 25, 2016 4:59 pm
Occupation: Parent

Kosher salt melts ice faster!

Postby lolola » Mon Jan 25, 2016 5:05 pm

I run an experiment twice and had same result and don't know why. 5 containers with the following: 15g ice cube and one of the following: 5g of kitchen salt, 5g of kosher salt, 5g of rock salt, 5 grams of Epson salt (magnesium sulfate), 5g of sugar. The control was a container with a plain ice cube. Both kosher salt and kitchen salt had the same caking agent. Kosher salt had slightly large particles than kitchen salt. Results: Kosher salt mel ice first, followed by kitchen salt, rock salt, Epson salt and finally sugar. Plain ice cube melted last. Why is that?

Former Expert
Posts: 70
Joined: Sat Dec 13, 2003 10:02 am

Re: Kosher salt melts ice faster!

Postby williamcolocho » Wed Jan 27, 2016 8:09 am


A quick google search gave this result for "Why does salt melts ice":

"In its pure state, water freezes at 0°C or 32°F. By using salt, that freezing point can be lowered which forces the ice to melt and prevents the water from freezing or re-freezing. It must be noted, however, that salt alone can't melt ice. It must first be combined with water to start the melting process."

"the amount by which the freezing point is lowered depends on the number of molecules dissolved, but not their chemical nature. (This is an example of what's called a "colligative property.")"

"In chemistry, colligative properties are properties of solutions that depend upon the ratio of the number of solute particles to the number of solvent molecules in a solution, and not on the type of chemical species present."

Return to “Grades K-5: Physical Science”