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Current time:0:00Total duration:4:17

Video transcript

a chiral objects are objects that are superimposable on their mirror images and in a minute I'm going to show you that a coffee cup is an example of an a chiral object chiral objects are objects that are not superimposable on their mirror images and the word chiral comes from the Greek word for hand and so I'm going to show you how your hands are not superimposable on each other but you're left in your right hand are mirror images of each other let's take a look at a coffee cup reflected in a mirror and so you can see on the left here is the actual coffee cup and in the mirror is the mirror image of the coffee cup and I'm going to pull out the coffee cup to make some space I'm going to put what I saw in the mirror the mirror image right next to it so we're here I have another coffee cup so that's its mirror image and I'm going to take the coffee cup on the right I'm going to rotate it and so as I rotate it you can see that it is super imposable with the object on the left right so the mirror image is super imposable and that's the definition of an a chiral object so we say that a coffee cup is a chiral now let's try the same thing with a molecule so this is Dai floral methane so the green are the fluorine atoms and in the mirror you can see the mirror image so once again I'm going to pull the molecule away and put what I saw in the mirror the mirror image right next to it and I'm going to rotate the mirror image so the one on the right I'm going to rotate it to see if it's super imposable with the one on the left and so I take it and as you can see as I rotate right right there you can see that it is super imposable with the molecule on the left and since the mirror image is super imposable we say this is an a chiral molecule so these are actually two of the exact same molecules represented here now let's look at my hands in my left hand and in the mirror you can see my right hand or what looks like my right hand so I'm going to take my left and my right hand together we just showed that there are mirror images of each other and then I'm going to try to rotate the my right hand to see if it's superimposed with my left hand and so you can see here I have my palms both up but my thumbs are not pointing the same direction so they're not superimposable here and so I'm going to try again I'm gonna try to rotate it right so now my thumb's from the same position but my palms are not in the same position and so no matter what I do I can never superimpose my right hand on my left hand so the mirror image is not superimposable upon the original object so no matter what you do you cannot you cannot accomplish this and since the mirror image is not superimposable we say your hands are chiral now finally let's take a look at a molecule so the widest hydrogen green is fluorine red is bromine and yellow is chlorine and so I had the molecules on the left and in the mirror is the mirror image so I'm going to pull out that molecule and once again leave some space and put what I saw in the mirror right right next to it so there's the mirror image so I have these these two mirror images of each other I take the one on the right and I try to rotate it to see if I can superimpose it with the one on the left and so here I just rotate it a little bit a little bit there and you can see that the the red the bromine atoms are in the same position however the chlorine and the fluorine the yellow and the green are not in the same position so I cannot superimpose it here I try again I rotate it some more and you can see the yellow is in the same position the chlorine and also the hydrogen's but the red and the green are not and so no matter how I rotate the mirror image the one on the right I can never get it to look like the one on the left and since the mirror image is not superimposable we say that this is a chiral molecule and this carbon here this is a very important carbon with four different substituents attached to it four different groups we call this a chiral center or a chirality Center