It doesn't change the amount of energy released. So the catalyst only speeds up the reaction. But notice that regardless of whether or not you have a catalyst, the delta H, the amount of energy released in the reaction, doesn't change. And even a small reduction in activation energy can make the reaction go thousands of times faster than it normally would. With a catalyst, my activation energy is a lot lower. Now let's see what happens when I add a catalyst. And delta H, that's the amount of energy that's released when the reaction happens. It's the amount of energy you need to add to the reactants to make the reaction go. The reactants are starting at this amount of energy and the products have this amount. So I've got potential energy on the y-axis and the reaction coordinate, or time, on the x-axis. I'm going to draw a potential energy diagram for this reaction. So let's talk about how a catalyst works. Then he added a catalyst, some manganese dioxide or MNO2, and got a plume of water vapor.
Dolhun had hydrogen peroxide in the plastic bottle. JESSICA HARROP: OK, so what happened? Dr. Now we're just going to lightly hold that. You can start to see some condensed water vapor forming inside the flasks. We're going to be using manganese dioxide.Īnd we're each going to take a scoop of this. And we're going to be using a man-made catalyst. We've got 15 mLs of hydrogen peroxide here. We're each going to do the experiment in a bottle. And basically what we've got is we've got four bottles. JOHN DOLHUN: So we're going to do this experiment here. Dolhun uses a catalyst to make the reaction go thousands of times faster than normal. But there are many ways to speed it up like increasing the temperature or adding a catalyst. Now, normally, you can't see this reaction happening because at room temperature, it's very slow. Now if you leave it alone, it decomposes into water and oxygen. It sort of looks like water, but the extra oxygen makes the molecule more reactive.
So it's called hydrogen peroxide and it's chemical formula is H2O2. The solution that you get at the drugstore is usually 3%. It's called hydrogen peroxide and it's the stuff you put on cuts.īut it has many other uses as well, from bleaching things to powering rockets, depending on its concentration. So you've probably seen this before at the drugstore or in your house. And today I'm going to be talking about a chemical demonstration I like to call the steaming gun.
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