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Hello, this is Hank Green, and welcome to SciShow experiments.  You know what I enjoy?  Water, and the being alive that it makes possible.  Our cells are constantly absorbing water through one of the simplest forms of chemical transport, osmosis, which is the solution of materials across a membrane.  And dissolved materials always follow the same rule, to flow from a region of high concentration to a region of low concentration.  The result is equal concentration on both sides of the membrane.

Now I'd be happy to volunteer one of my cells to demonstrate this to you, but It'd be a lot easier to use an egg, for a bunch of reasons.  First, the size.  My cells are tiny, very difficult to see, but an unfertilized chicken egg is actually a cell.  A huge single cell.  In fact, at any given time, the largest cell on earth is an ostrich egg.

The egg's innards, the yolk and the whites are contained within a membrane, just under the surface of the eggshell, that's much like the membranes of my cells.  Also the innards have a high concentration of protein and fat dissolved in them, so they'll tend to absorb water to create that balance I was talking about.  But to get to the membrane, first we have to dissolve the shell, and that lets us do some really sweet bonus chemistry, and in the end, we'll have something that looks like an alien's gonna hatch from it.

 All you need is an egg, a cup of vinegar, a cup of corn syrup, and a couple of days.  Sorry, but science takes time. Start by immersing the egg in a cup of vinegar.  This is where the chemistry comes in, about four to eight percent of vinegar is acetic acid, the rest is water.  Meanwhile, about ninety five percent of the eggshell is calcium carbonate, which you also know as chalk or lime.

The acetic acid dissolves the calcium carbonate by swapping out the carbonate for acetate, and it becomes calcium acetate, along with some water and another by-product you can see forming after a few minutes, carbon dioxide.  After a few days the vinegar has completely dissolved the eggshell, leaving only the membrane to keep the contents of the egg, which are still raw, mind you, together.  You can even hold this uncooked, shell-less egg in your hand.

But, something strange has happened.  The egg is now larger than it was yesterday, what is up with that?  The egg's membrane is slightly permeable, which means that only some material can pass through.  Remember, vinegar is mostly water. And though the acetic acid can't break down the cell membrane, the water in the vinegar was able to permeate the membrane and flow into the egg, going from vinegar's low concentration of dissolved material into the higher concentration inside the egg.

As a result, the egg absorbed the water through osmosis, making it big, and gross, and kinda alien looking.  But what if you wanted to reverse that process, to draw the water that's now inside the egg, out of the egg?  Well, you'd have to put it in a solution with a higher concentration of dissolved material in it.  Something like, maybe really salty or really sugary.

To try that out, immerse the big alien egg in a cup of corn syrup.  This is an extremely sugary solution, compared to the solution inside the egg.  After another day, you'll see that the alien egg has gotten even more gross.  The water has flowed out of the egg and into the syrup, leaving the egg's innards inside a wrinkly, gross membrane.

Egg, vinegar, and corn syrup, a disgustingly delicious recipe for freaky cool science and a better understanding of osmosis.

Thank you for watching SciShow Experiments.  If you have other ideas for experiments or questions or comments or ideas or anything, we're on Facebook, and Twitter, and of course in the comments below.  And if you wanna keep getting smarter with us here at SciShow, you can go to youtube.com/scishow and subscribe.

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