Good you're absorbing, so it's kind of the opposite. You're transmitting a lot, but absorbance is how And so here, we're trying to measure, how good is it at absorbing? This is measuring, how goodĪre you at transmitting? A higher number says Transmittance, and we'll see, it has pretty neat properties, Which is really kind of a derivative of the transmittance, and not in the calculus sense, it's just derived from So this will have the least transmittance, it's the most opaque, followedīy that, followed by that. Number, followed by that, followed by that. The light that goes in, and this is the smallest The light that comes out, that gets through, over I2 is lower than I1, so this will have a lower Would be the amount that you got out over theĪmount that you put in. Transmittance of number one would be the amount that got through over the amount that you put in. Let's just define transmittance as that ratio. Is how much is transmitted versus how much went in, so Who defined it said, well, you know, what we care about So the first thing I willĭefine is transmittance. Much light is transmitted versus how much was put in. Really, some terms of ways of measuring how concentrated this is, or ways of measuring how Of that in the next video, let me just define some, So before we do that, and I'll show you an example That's why we're even talking about it in a chemistry context. In to actually figure out the concentration of a solution. Light is transmitted versus how much you put And so the next question is, well, what is it even good for? Why would I even care? Well, you could actually So hopefully, that gives you the intuition behind spectrophotometry. In, gets even longer, it'll get even more opaque. And if the cup that you're dissolving in, or the beaker that you're Of something in water, it'll be more opaque. If you dissolve a little bit of something in water, it will This would be a slightly darker color, and this would be the darkest color. So if you were to look at this, if you placed your eyeball right here, this one right here would Light being transmitted, this has the most light being transmitted. These, this has the least light, this has a little bit more So I2 is less than I1, and I3, I3 is actually going to be the least. To bump into more molecules and more of it will be absorbed, and so less light will be transmitted. What do you think's going to happen? Well, it's the sameĬoncentration, but this light has to travel a furtherĭistance of that concentration. Makes it through, that exits, and then this is actually The same light in here, and you have some light that Look fairly similar, and you were to shine some light in here. Two, we'll call this one number three, it has the sameĬoncentration as number two. Let's say it has the same concentration as number That is maybe twice as wide, it's twice as wide, and To have a lower intensity, is going to be less than I1. That's being transmitted than this one over here. So the light that comes out when you have a higher concentration, I'llĬall that the intensity, I'll call that I2, this is going to have a lower intensity of light Into more molecules, 'cause it's a higher concentration here. Same intensity of light, what's going to happen? Well, more is going toīe absorbed as the light travels through this beaker. It's the same number that is, that is the same, the We shined the same amount of light into this beaker, so What's going to happen as the light exits the other side of this beaker right here? Well, some of it is going to be absorbed by our little molecules inside the beaker, so you're going to have less light come out to the other side. Sensitive to the solute that we have dissolved in here. Through each of these beakers, and let's just assume that weĪre shining at a wavelength of light that is specific to the. Now let's think about what will happen if we shine some light Concentration, and let's say, and this is a lower, lower concentration. So I'll just kind of represent that as more closely packed lines. Two has more of the solute, so it's more. So this guy has less of it,Īnd let's say it's yellow, or to our eyes, it looks yellow. Now let's say that solution one has less of the solute in it. And let's just assume that ourīeakers have the same width. We have two solutions that contain some type of solute. Spectrophotometry, photometry, which sounds fairly sophisticated, but it's really based onĪ fairly simple principle. To do in this video is to talk a little bitĪbout spectrophotometry.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |