So let's throw some solute there, and I'll actually throw a little bit of solute here too. Thinking about the membrane as only allowing certain things of certain size to pass through. There's other ways where you could have semipermeable membranes that use charge to allow certain things to pass through and not others, but it's easier to visualize the size. And I'm gonna make them bigger so you can see they would physically have trouble passing through these gaps. So let's throw some solute particles here. Let's treat our water as solvent, and let's put some solute in it. The probability of going from left to right through one of these gaps is going to be equal to the probability of going right to left in any given period of time. We just sort of think about it probabilistically. They have different speeds and in different directions. And these things are all bouncing around in all different ways, they all have, they all are, they all have different velocities. The water molecule, since we have an equal concentration on either side, the probability that one of these water molecules goes this way in a certain amount of time is equal to the probability that a water molecule goes from right to left in the same amount of time, and that's because we have equal concentrations. We've already talked about it in the videos on diffusion. Let's just think about what would happen if we just had water molecules on either side. Let's say this semipermeable membrane, it does allow water molecules to pass, and in a few seconds we'll talk about what it does not allow to pass, which makes it semipermeable. Now what do I mean by semipermeable membrane? That means they allow some things to go through and not other things. Let's say that I had two compartments of water, and they're separated by a semipermeable membrane.
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