M & M's!

Ah, so many lab choices with solubility.  So many things one can do...

I stumbled upon this GREAT website: http://www.inquiryinaction.org/classroomactivities/topic.php?topic=Solubility

DAY 1:  So, we started out by finding out if temperature makes a difference in the rate that an M & M's colored coating dissolves in water.  Students designed their tests, and most of them chose to test the SAME colored M & M (controlled variable) and the SAME amount of water (controlled variable).  They filled one container with hot water and one with cold.

Here is a picture of one group's containers:

It's not hard to see that very little of the colored coating is left in the hot water, and more is visible in the cold water.

This lab led to a discussion about what students already know about molecules and how they move when hot vs. cold.  Students quickly understood why the hot water would dissolve the M & M colored coating faster.

DAY 2:  Next, students had to see if a solution of sugar would make a difference in the rate that the colored coating of the M & M's dissolved.  The controlled variable were the color of the M & M's, amount of water, and the temperature of the water.

Put the M & M's in...

It doesn't take long to see the color on the bottom of the bowls.

You might not be able to tell in the picture, but the bottom of the "no sugar" bowl is covered lightly in green, the "1tsp sugar" bowls is green around the outside, and the "3 tsp sugar" bowl is green in a crescent shape.  Therefore, the "no sugar" M & M coating dissolved the fastest, and the "3 tsp sugar" bowl dissolved the slowest.  This happened, because the sugar solution is MORE DENSE than the water, so it is harder for the candy coating to "push" on the solution than the water.

More FUN in science!  Learn on, kids!