1 00:00:00,000 --> 00:00:04,365 [BEAKER STIRRING] 2 00:00:04,365 --> 00:00:09,430 [LAUGHTER] 3 00:00:09,430 --> 00:00:41,370 [MUSIC PLAYING] 4 00:00:41,370 --> 00:00:44,970 ANNOUNCER: It's day two of 5.301. 5 00:00:44,970 --> 00:00:47,340 The students are given a tenth of a gram of Ethyl 6 00:00:47,340 --> 00:00:50,980 3-hydroxybenzoate contaminated with a small amount of 7 00:00:50,980 --> 00:00:52,440 triethylamine. 8 00:00:52,440 --> 00:00:55,000 The goal is to separate the contaminant from the target 9 00:00:55,000 --> 00:00:58,370 chemical using a technique called extraction. 10 00:00:58,370 --> 00:01:01,500 The students first dissolve the mixture in ether, then 11 00:01:01,500 --> 00:01:03,190 they add an acid solution. 12 00:01:03,190 --> 00:01:06,700 Acid and ether don't mix, so two layers form. 13 00:01:06,700 --> 00:01:09,870 As the students shake the mixture, the acid reacts with 14 00:01:09,870 --> 00:01:12,330 the contaminant to form a salt. 15 00:01:12,330 --> 00:01:16,800 This salt is much less soluble in ether than it is an acid, 16 00:01:16,800 --> 00:01:20,430 so it moves from the ether to the acid. 17 00:01:20,430 --> 00:01:23,930 The two liquids separate back into two layers. 18 00:01:23,930 --> 00:01:27,980 Overall, the target molecule stays in the ether and the 19 00:01:27,980 --> 00:01:31,400 contaminant moves to the acid layer. 20 00:01:31,400 --> 00:01:32,290 ANTHONY: This has my product. 21 00:01:32,290 --> 00:01:34,040 This has my impurity. 22 00:01:34,040 --> 00:01:36,300 ANNOUNCER: Now it's time to head over to the rotovap to 23 00:01:36,300 --> 00:01:37,550 evaporate the ether. 24 00:01:44,820 --> 00:01:47,180 Anthony starts rotovapping, and it's all 25 00:01:47,180 --> 00:01:48,940 going well, for now. 26 00:01:53,332 --> 00:01:54,800 But after a while-- 27 00:01:54,800 --> 00:01:56,500 ANTHONY: I'm not getting any of my dried 28 00:01:56,500 --> 00:01:58,750 sample on the edges. 29 00:01:58,750 --> 00:02:01,790 I think as long as there is still ether in there, then I 30 00:02:01,790 --> 00:02:05,510 won't get anything to show up, is what I'm hoping. 31 00:02:05,510 --> 00:02:08,669 IKE: His was a lot and it's not succeeding. 32 00:02:08,669 --> 00:02:13,412 Mine is little, so what chance do I have? 33 00:02:13,412 --> 00:02:15,595 ANTHONY: I thought I did something wrong and, of 34 00:02:15,595 --> 00:02:17,580 course, no one wants to do anything wrong, especially on 35 00:02:17,580 --> 00:02:18,802 the second day. 36 00:02:18,802 --> 00:02:20,910 I should have gotten some product. 37 00:02:20,910 --> 00:02:24,040 I went to Tengfei, and I was like, look lady, I don't know 38 00:02:24,040 --> 00:02:26,945 you very well but this doesn't seem like it's working. 39 00:02:30,070 --> 00:02:33,150 She drained the solvent and then turned 40 00:02:33,150 --> 00:02:35,650 on the vacuum again. 41 00:02:35,650 --> 00:02:36,900 I still don't see anything. 42 00:02:41,110 --> 00:02:43,270 Everyone else was getting their samples and they were 43 00:02:43,270 --> 00:02:45,510 going to dry and then mass. 44 00:02:45,510 --> 00:02:48,170 And I was like, I don't have anything. 45 00:02:48,170 --> 00:02:50,550 ANNOUNCER: Anthony's troubles finally get Phil's attention. 46 00:02:50,550 --> 00:02:53,120 PHIL: Try putting it on one of the other rotovaps. 47 00:02:53,120 --> 00:02:54,990 ANNOUNCER: Phil thinks the rotovap Anthony is 48 00:02:54,990 --> 00:02:56,460 using must be broken. 49 00:03:05,590 --> 00:03:08,360 ANTHONY: And I start getting crystals, I guess, on the side 50 00:03:08,360 --> 00:03:09,780 of my round bottom. 51 00:03:09,780 --> 00:03:10,220 I clutched my heart. 52 00:03:10,220 --> 00:03:12,420 And I was like, finally. 53 00:03:12,420 --> 00:03:15,380 ANNOUNCER: But the sample doesn't quite look right, and 54 00:03:15,380 --> 00:03:17,517 Tengfei has something to say about that. 55 00:03:17,517 --> 00:03:20,930 TENGFEI: Who's to know what you are supposed to get? 56 00:03:20,930 --> 00:03:23,080 ANTHONY: So she's like, calm down. 57 00:03:23,080 --> 00:03:24,260 Like, just hold on. 58 00:03:24,260 --> 00:03:25,590 You don't even know what you're supposed to get 59 00:03:25,590 --> 00:03:27,600 yet, so hold on. 60 00:03:27,600 --> 00:03:29,660 ANNOUNCER: Anthony runs an NMR to figure out 61 00:03:29,660 --> 00:03:31,680 exactly what he has. 62 00:03:31,680 --> 00:03:32,620 ANTHONY: Check this out. 63 00:03:32,620 --> 00:03:35,000 This doesn't look like it's horribly wrong. 64 00:03:35,000 --> 00:03:38,210 So, hopefully this will be it. 65 00:03:38,210 --> 00:03:42,310 I think this is a pretty good NMR scan. 66 00:03:42,310 --> 00:03:44,610 ANNOUNCER: Even though his sample looks different, the 67 00:03:44,610 --> 00:03:47,280 NMR spectrum matches that of the pure compound. 68 00:03:50,570 --> 00:03:52,210 ANTHONY: 70% yield. 69 00:03:52,210 --> 00:03:55,880 So not wonderful, but not too bad. 70 00:03:55,880 --> 00:03:58,440 When I got a sample and I got a pretty big yield and it was 71 00:03:58,440 --> 00:04:01,680 pretty pure, I was happy. 72 00:04:01,680 --> 00:04:02,760 ANNOUNCER: And that's it. 73 00:04:02,760 --> 00:04:04,255 The first day is done. 74 00:04:08,150 --> 00:04:09,900 EMILY: Overall, I think the lab was OK. 75 00:04:09,900 --> 00:04:14,940 It was a little stressful at times, but we all made it 76 00:04:14,940 --> 00:04:19,410 though it alive and I think it will just get easier with each 77 00:04:19,410 --> 00:04:20,815 day as we become more comfortable 78 00:04:20,815 --> 00:04:22,350 with what we're doing. 79 00:04:22,350 --> 00:04:23,710 ETHAN: I'm definitely not as nervous anymore 80 00:04:23,710 --> 00:04:24,990 to go to the lab. 81 00:04:24,990 --> 00:04:27,380 I'm actually more excited for it, I guess. 82 00:04:27,380 --> 00:04:28,730 ANTHONY: I'm looking forward to tomorrow. 83 00:04:28,730 --> 00:04:30,485 It's going to be a lot harder, but I think it's going to be a 84 00:04:30,485 --> 00:04:31,735 lot of fun. 85 00:04:36,160 --> 00:04:37,410 PHIL: I'm not a gambling man. 86 00:04:41,940 --> 00:04:44,890 I do slot machines. 87 00:04:44,890 --> 00:04:58,859 [MUSIC PLAYING]