An osmotically active substance is best understood by learning that osmosis is the movement of water from areas of high concentration to areas of low concentration. Find out how osmotically active substances cause osmosis to occur with help from a science teacher and field biologist in this free video on chemistry.
Hi, I'm Brian with Ericksontutoring.blogspot.com, and today we're going to define an osmotically active substance. So, first of all, osmosis is a form of simple diffusion, and essentially osmosis is the movement of water from areas of high concentration to areas of low concentration. Now, the question at hand, what is an osmotically active substance. That, would be if you put something into water, and there's a membrane dividing it, the substance and that would be, would cause osmosis, so say you put a block of sugar into water. As it dissolves, it's going to break up and the process of osmosis, water is going to move in to where you put the sugar, to sort of balance out the gradient, and because the sugar causes osmosis to happen, it's an osmotically active substance. Other examples would be salt, all sorts of sugars, basically anything that you're going to throw in to, to make a solution. And, that was a definition and discussion of osmotically active substances.