 Collegative properties have a lot of practical applications. One application that I want us to discuss is that of antifreeze. Antifreeze is something that you put in your car radiator to keep the water in the radiator from freezing in the wintertime. And to test your antifreeze, you use a little tester. This tester is calibrated in Fahrenheit, and if one ball floats, it says your antifreeze is safe to plus 20 degrees. If two balls float, it's plus 5 degrees. Three balls minus 10, four minus 25, and five minus 40. What we're going to do is to use a tester and test some sample radiators. And if you look at these, you think you may have enough antifreeze, but we need to test to see how safe it is. So let's start with this one. And what I'm doing is just pulling some of the solution up into this container right here. And then we want to see how many balls will actually float. In this one, no balls are floating. So even though this is green, this radiator is not safe. In this one, one ball floats. In this solution, two balls float. In this solution, all five of the balls are floating.