First semester of orgo - having a panic attack!

[Shrami]

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Are there any supplimentary books that anyone recommends I use. The book we use is okay, but not nearly enough. We are just on the first few chapters. My impression was that the first 2 weeks or so would be a piece of cake, but it's not that easy.
Any books that could help?

 

[bbas]

Well, I'll give you the same advice that my professor told us. He said that it was a waste of money to buy any supplimentary books, because every professor teaches the course differently and puts their own "spin" on the material. Also, most professors will only test you on info from their lectures and types of problems that are found in the textbook that you are using. If you definitely want other sources, then I would look for some study guides on the internet. There's some good ones online.

 

[fiddler]

Organic chemistry is about interactions between organic molecules.

Believe it or not there are only specific molecules that react to each other and very specific reasons why.

get "Pushing Electrons". Do the first 3 chapters at least twice and understand why you are doing. It will build a good foundation for orgo.

fiddler

 

[Bluntman]

Organic chemistry is about interactions between organic molecules.

Believe it or not there are only specific molecules that react to each other and very specific reasons why.

get "Pushing Electrons". Do the first 3 chapters at least twice and understand why you are doing. It will build a good foundation for orgo.

fiddler

*cringe* that book conjures up all sorts of bad memories. I agree that's a solid recommendation to get when you're in 1st sem ochem tho.

 

[63768]

first of all, calm down. orgo is as hard as you make it. just study. take the time and study. it's often a premed weed-out class so deal with it.

 

[fiddler]

*cringe* that book conjures up all sorts of bad memories. I agree that's a solid recommendation to get when you're in 1st sem ochem tho.

how come?

I was so bored in physics that I did those exercises in physics class. lol. It made the time pass faster and i learned something.

fiddler

 

[Bluntman]

how come?

The book was a good learning tool, but thinking about it still brings back all the not-so-wonderful memories from a year of ochem. 🙄

 

[AznDoc]

i think o-chem is going to take some work but not an impossibility for an A. however, things got bleak when i realized that the instructor that said TBA on my schedule is actually a freshly minted phd from taiwan with indiscernible english...

 

[fiddler]

The book was a good learning tool, but thinking about it still brings back all the not-so-wonderful memories from a year of ochem. 🙄

thats too bad. Although I had to study like crazy sometimes, I really liked it. I learn a lot and now I understand studies in molecular and biochemistry that I read.

fiddler

 

[Mutt]

We need to remove "orgo" from the pre-med lexicon.
It is too brutal of a subject to have such phonetic similarity with something so.....fun.

"O-Chem!"............call it "O-chem!"

 

[DrBowtie]

After having my third lecture monday, I am beginning to hit where hell starts.
IR and nomenclature. Chapter 2 in the solomon's book. It is like 150 new things all that just have to memorized.

Just study everyday. Thats what's keeping me up to speed.

 

[fiddler]

Solomon & Fryhle is a good book. That is what we used. I suggest that you do the exercises at the back of the chapter to cement your knowledge. I wouldn't do all of them, that would be overkill.

Know your orgo. It makes biochem ridiculously easy.

fiddler

 

[Dave_D]

Solomon & Fryhle is a good book. That is what we used. I suggest that you do the exercises at the back of the chapter to cement your knowledge. I wouldn't do all of them, that would be overkill.

Know your orgo. It makes biochem ridiculously easy.

fiddler

It is? I thought it was terrible, especially in the later sections. (Ok, so I just finished up Orgo II and found the book to be rambling, loads of idiotic questions etc.) I agree doing the problems is a big part of the course.(Since often information that should have been introduced in the chapter is actually introduced in the questions. (Although too many questions really should have been in a different chapter or were just utterly pointless.)

I guess there were just less NSS statements in the book.(But guess I can't have everything.)

 

[Jon Davis]

Take a chill pill and relax.
Read the text and get help if necessary.

 

[Dave_D]

After having my third lecture monday, I am beginning to hit where hell starts.
IR and nomenclature. Chapter 2 in the solomon's book. It is like 150 new things all that just have to memorized.

Just study everyday. Thats what's keeping me up to speed.

Yes, that's pretty much all you can do. Fortunately the memorization goes down a bit for awhile.(Memorization doesn't really pick back up until 7 and 8)

BTW if anybody tries to convince you that memorization is not a significant part of the course absolutely do not believe them.(Not saying the course is only memorization.)

Oh quick question Brett, you're a UMass student right? Are you taking this at the school?

 

[DrBowtie]

Yes, that's pretty much all you can do. Fortunately the memorization goes down a bit for awhile.(Memorization doesn't really pick back up until 7 and 8)

BTW if anybody tries to convince you that memorization is not a significant part of the course absolutely do not believe them.(Not saying the course is only memorization.)

Oh quick question Brett, you're a UMass student right? Are you taking this at the school?

I'm not a UMASS student. Sorry.

 

[teedub]

i'll agree with the electron pushing thing. after that, it's all about memorization (the same stuff that'll probably float you in med school). my advice is, do as many synthesis rxns as possible (in solomon's book, they're at the back of the chapter), do them daily, and even make up some as you go. synthesis is probably the hardest part of organic, so if you can get that you'll automatically have a grasp on anything simpler.

 

[DrBowtie]

Due to the teacher missing lecture for a conference and labor day,
My first test on wed. is only over chapters 1 & 2 (except the IR). I am in heaven 🙂

 

[Twitch]

Well we're into our second week of Orgo I and the prof just started chapter 3 of McMurry. My first official lab is tomorrow and my TA has got to be the most anal is the world. He has these strict rules:
- pencil in your lab notebook - you loose points,
- don't have hardbound notebook - you loose points,
- use wite-out - you loose points,
- breathe without permission - you loose points 🙂

J/k on the last one but seriously, this guy is giving us the impression that compliance is expected fully - you stray you die is the message he sent home. Needless to say, I'm dreading lab tomorrow. It just seems like a lot of work for a measly 1 credit hour lab.

Lecture is going good. It certainly helps to keep up with the reading and the fact that I went through the nuts & bolts of organic chemistry (recommendation from amazon) sure helps. I would like to get more practice with net dipole moments (esp in 3D) and resonance structures. I'm planning to tackle the end of ch-2 problems this weekend. Even though I have Organic as a second language I have barely touched it. The Nuts & Bolts book gave me a good introduction and my Gen Chem text helped refresh me on the good ole sp2, sp3 & sp hybridizations. Other than the needed practice I honestly don't see what the big deal with Organic is.

I do hate the way the prof is condescending to the students that ...OMG y'all should be so afraid... y'all know nothing... I'm god cause I'm teaching you organic. Ha!

Regardless, the lecture content itself is interesting (despite the prof). Second the SI - supplemental instruction is awesome. The guy goes through a bunch of problems and we spend the entire session doing that. Right now the sessions are very small in class size. There is me and a chic. There used to be a another guy in the SI class but he doesn't show up anymore. I imagine we'll see more kids come to SI after they see how the first test is like.

 

[DrBowtie]

I just came back from Lab :goes to room to cry:
During the worst 4 hours of my life thus far, I couldn't get my sample to recrystal. I finally did at the end of lab and didn't get to filter it multiple times giving me a whopping 7% yield. Also we had to measure the melting point and pick it out from a list of unknowns. My experimental melting point was exactly in between 2 choices. I am going to have to do a bit more research to find out which I think it will be.
Lab sucks!
:end rant:

 

[Dave_D]

Oh we had all those rules as well but if I remember correctly our lab manual explained why. Basically it's along the lines of what the other fellow said, basically they were trying to give you an education in actually doing science. (If you're taking Orgo you're probably either in chem, bio, or a premed so you'd better get used to doing science.) So they had all those rules so others could look at your documentation and figure out what you did and repeat the experiements from your notes if necessary. (Or so you could redo your experiements.) So that's why it's that way, no erasing or destroying raw data and you need to be fairly serious. In our course you were expected to write up what you were going to do (Basically transcribe the lab text into your notebook in your own words) and include a table of chemicals used in the experiement so you didn't have to look up anything.(Yes, I literally had a table that listed chemical names, showed the formula, had the boiling point, melting point, density and atomic weight.) Then do the experiment and document what you did and finally write a conclusion of what happened.(It made doing lab reports pathetically easy since you just turned in notebook pages.)

Brett, try to not let lab get you down since I think alot of us have the lab from hell.(In my case I had to repeat one lab 3 times before I finally got the reaction to work. Admittedly it was closer to the begining of the experiement though.) Just be quick and flexible when doing the experiment so you can redo parts of it if necessary. (But damn does it suck when the experiement just starts fighting with you.) I hope they're not grading to heavily on yield and purity though. (Since that can be so squirrelly.)

 

[DrBowtie]

Brett, try to not let lab get you down since I think alot of us have the lab from hell.(In my case I had to repeat one lab 3 times before I finally got the reaction to work. Admittedly it was closer to the begining of the experiement though.) Just be quick and flexible when doing the experiment so you can redo parts of it if necessary. (But damn does it suck when the experiement just starts fighting with you.) I hope they're not grading to heavily on yield and purity though. (Since that can be so squirrelly.)

Thanks for the reassurance. We can drop one of our lab report grades and the TA said most drop the first so I am feeling much more at ease.

On a side note does anyone use the Zubrick Lab Manual?

 

[fiddler]

Brett,

your had trouble in the lab because you didn't prepare properly for it.

Read the lab manual. Then read zubrick on how to do the lab. Make sure you understand it and then write up the lab in your notebook.

Oh yeah, get all the data on all the stuff you will be using in lab. mol wt, bond line, melt pt, etc.

Once you get in the lab, you should know exactly what you are going to do.

I actually spent about 1/2 to 2/3 the time in lab than everyone else because i go in prepared to roll. It really helps the learning process. otherwise it's one giant 4 hour frustration period.

fiddler

 

[DrBowtie]

I had the technique down. My problem was in the wishy washy words in my lab manual like "indeterminable time" to let the solution cool both to touch and then in the ice bath. It is also hard since this was the first time finding everything in the lab. I had to add solvent, cook it down, add more solvent too many times.

With this lab we were determining unknowns so the m.p. and weight and such couldn't be gotten beforehand. However, I will look this up to help make the determination of my unknowns that have a few possibilities based on m.p.

Overall, I could have done worse and I could have done better. Thanks for the advice.

 

[fiddler]

you should look up all of your data on chemfinder.com first. all data you need should be available on hand. I believe you should have a thermometer in your drawer. If you look it up in zubrick, there is a lot less guessing.

heck if the website doesn't have it, google it and see what happens.

It makes the lab fun and a great learning experience.

fiddler

 

[Twitch]

I'm all about documentation. My beef is with the archaic method of documenting. Perhaps I'm being iconoclastic but surely someone else has to see the inefficiencies of this protocol.

Ahh well, first lab in 10 minutes. Now Brett has me worried...thanks a lot 😡

 

[Dave_D]

you should look up all of your data on chemfinder.com first. all data you need should be available on hand. I believe you should have a thermometer in your drawer. If you look it up in zubrick, there is a lot less guessing.

heck if the website doesn't have it, google it and see what happens.

It makes the lab fun and a great learning experience.

fiddler

Wow, beat me to it. That was one of the first things the lab professor told us about. It was definitely a huge help for the course, I'd hate to think what the lab would have been like if I didn't have that resource. Oh we also used Zubrick and it was reasonable clear.(Although I thought theoretical plates could have been stated more clearly. However after the first semester I hardly touched the thing.)

Still Brett I'm still wondering what they're doing, sounds like the labs arn't as well run as they should be. I mean they didn't even give you a check in period?(When I took lab the first lab was simply assigning you a drawer and then having you make sure you had everything by going through a check list. Theoretically if everything was perfect it should take a half hour. Of course in my case I was missing loads of stuff so it took one and a half after I figured out what was missing and got it from the stockroom. I'd hate to think what it'd be like to do a lab after that.) Also they didn't give you specific times for reactions Our lab book would pretty much tell you how long to run the reaction and what you should see.(Well ok sometimes they wouldn't but that was the unspoken rule that went "If we don't tell you how long to run a reaction that means 5 minutes.") The info was pretty helpful though.(The reason I knew my lab wasn't working is that they would tell you that you should see color changes or precipitate and when I saw nothing of the sort I figured something messed up.) Do they at least tell you what you should see.(If so definitely write those down, I think a couple of labs had multiple color changes and if you went the first you'd be in trouble.)

Seriously though Brett it sounds like you're doing the prep work and it'll just be a matter of moments before the labs start to go well for you.(And basically just blow by everyone that hasn't prepped.) Anyway I hope they're keeping a similar grading method as UMass.(Never actually stated but I got the impression our products were only worth about 10% of the lab grade. Being prepared, keeping good notes and being prompt on turining in our lab reports and prelabs were the vast majority of our grade.)

Quick question, are they going to give you a lab quiz and is it open notebook?(Because if it was like our lab if you do the prep the quiz is actually easy.)

 

[Dave_D]

I'm all about documentation. My beef is with the archaic method of documenting. Perhaps I'm being iconoclastic but surely someone else has to see the inefficiencies of this protocol.

Ahh well, first lab in 10 minutes. Now Brett has me worried...thanks a lot 😡

I know, it seems a little much and at this level it probably makes no sense. However if you remember that reproducibility of results is a big thing in science and they are trying to get you used to that. The point is that if you end up being a real scientist and you make some big discovery someone else should be able to reproduce the experiement and get the same results. So the point is to write down everything you did so if you wanted to redo the experiement, let your buddy 2 offices down, or some guy on the other coast all you'd have to do is photo copy the lab manual and fax it. Admittedly nobody at our level is going to do this but they want you to get used to the technique so that years down the road you will do this.(At least that's what they told us, YMMV.)

 

[DrBowtie]

We did have check in period but that only accounted for the things in our drawers. There were some pieces of equipment that they have as community pieces so they only have to buy 32 vs. 160 (for all drawers) that I didn't know where they were.

We don't have quizzes but we do have a pre-lab based off of the relevant chapters in the Zubrick Lab book. Also we must have a written procedure column pre-made so we can take observations side by side.

I was told that for this first lab accuracy doesn't weight too heavily due to a slight learning curve. Nonetheless since we were measuring unknowns anything could have occured.

 

[DrBowtie]

First lecture test tomm. 5:30 pm EST. Wish me luck!!!!

I'm not too worried since it is just over a small amount of material but nonetheless it is the dreaded Organic so I am expecting the worst.

 

[SeventhSon]

Thanks for the reassurance. We can drop one of our lab report grades and the TA said most drop the first so I am feeling much more at ease.

On a side note does anyone use the Zubrick Lab Manual?

lol, no. The exact same thing ahppen to me and I knew what i was doing. Some compounds are ******ed and the second the solvation liquid is taken off the hotplate the crap immediately precipitates. I remmeber my yield for recrystlatization was 8%. Beat ya

[edit] i meant to respond to fiddler's post

 

[beastly115]

I have my first quiz over chapter 1 this Friday. We use Bruice and I don't think it's a bad book. So far so good 👍

Chapter 2 starts nomenclature

 

[Dave_D]

Good luck guys. From what I remember the first couple of chapters aren't too bad and there is some old stuff. I've mentioned this before but quite a bit of the stuff you've seen you will not see again until semester 2. Now things will be a bit different in 6-8 weeks 🙂 .(Ok, I got annoyed later on when stuff got harder yet they kept up with the ******ed statements like "nucleophile" and "Zaitsev's rule." If anybody cares I can tell you why this stuff is "******ed".)

 

[DrBowtie]

Test went well although I was pressed for time a bit. 90+ though I think.

 

[DrBowtie]

resonance, formal charge, functional groups, solubility, hybridization...etc.
Mostly gen chem stuff with some actual organic. We have only had 4 lectures and 2 were with the TA since the prof was at a conference.

 

[atrovariousg]

Are there any supplimentary books that anyone recommends I use. The book we use is okay, but not nearly enough. We are just on the first few chapters. My impression was that the first 2 weeks or so would be a piece of cake, but it's not that easy.
Any books that could help?

It's all greek isn't it. I'm retaking it 10 years later and it seems like review, but the first time through I was a bit overwhelmed as well. Best tip is to stay ahead that way the lecture seems to be more easy to swallow.

 

[Twitch]

Good luck! Ours is next Friday (9/16)!

So we're starting Ch-4 and our first test is next thursday 9/15.

 

[lemonlite]

Talk to your TA. Read "pushing electrons". Try to understand why things react - resonance structures, stability, ect. This class is a fun puzzle think about it that way and you won't be intimidated. Once you understand the chemistry - and trends, memorization is easy. Just wait until you get to NMR - the best puzzles ever...

 

[fiddler]

I had forgotten about NMR. The puzzles were fun. You get a NMR and IR chart and you have to figure out the molecular structure.

Pay attention to the LUMO stuff and how light interact with electron structures. In the second semester, you actually get to synthesize organic molecules and it is really cool to be able to understand why the stuff looks shiny.

If you prepare well, you will also find it amusing to see other people make sludge from their experiments. You can try to help but by then, it's usually too late. Those reactions are very one way!

fiddler

 

[loveumms]

I love reading the pre-med forum because it always brings back such "wonderful" memories ... O-chem being one of them.

I wouldn't recommend buying extra books because you probably won't have all that much extra time and trying to find a good book that adequately explains all the material you will be expected to learn is next to impossible.

My best advice - make NOTECARDS! I think that was my saving grace as an undergrad. When you are walking around campus with nothing to do (ie you don't have anyone to chat with) flip through the notecards. You will be surprised at how much you can learn in just five minutes, plus all those five minutes add up to quite a lot of study time. To be honest, this was how I studied as an undergrad (never picked up a book past 7 pm and never studied on weekends).

I can remember what a pain in the a** it was to memorize all those reactions and structures but just realize that this is priming you for med school where you will have to memorize 100 times the material you are expected to know in O-chem. And, event though its hard to believe this is definitely a weed out class ... at my school about 10-15% of the people who were "pre-med" were not with us by the end of the first semester. Its a tough class!

Its kinda funny, I remember hating the class but by the end of the year I actually ended up liking it and really understanding the material.

Best of luck 😉

 

[Anastasis]

Today will be my 3rd real lecture and we're just now finishing Ch.1 in Solomon's - assuming we finish it today. Brett is right - it's mostly Gen Chem with a bit of O-Chem thrown in, really easy stuff though I guess I should enjoy it because I am sure it's all downhill from here. Our first exam is the 27th and I think it's only over 3 chapters (so you can see the excruciating slow pace we're going at). 😴

BTW, I might be joining in the Lab woes later in the semester but our first lab was one macroscale fractional distillation and the only hitch was when my lab partner broke a beaker containing tolulene and cyclohexane all over me. On top of that, my lab professor says that accuracy doesn't matter as long as you know what you did wrong and include it in the write-up. Hells yeah. 😀

 

[DrBowtie]

Today was another lab. Determination on an unknown liquid went well but my microscale recrystal got cleared as no results. All of my crystals were grainy and couldn't be gotten off of the filter paper.

For future reference any tips for recrystalization when it gets gritty?

 

[Dave_D]

Today was another lab. Determination on an unknown liquid went well but my microscale recrystal got cleared as no results. All of my crystals were grainy and couldn't be gotten off of the filter paper.

For future reference any tips for recrystalization when it gets gritty?

Gets gritty? You mean you're getting garbage in your samples or something? I never really had that problem. Basically I just do the standard stuff. So step one triple check that I had the right solvent.(Because later on it's so damn easy to use the wrong one.) Step two put the solvent in one erlynmyer(sp?) flask and the crystals in another and heat up both flasks until the solvent is borderline boiling.(Apparently trying a regular beaker instead of an e-flask is just asking for trouble. At least that's what Zubrick talks about.) Step 3 use a clean pasteur pipette to add the solvent dropwise to the solid until everything just barely disolves.(You should see absolutely no precipitate in the solution. Usually the solution will have a color but no specs or anything like that.) Step 4 let cool to room temperature, seeding it if necessary.(And the manual probably should mention that. Not hard to do but sometimes necessary.) Finally step 5 ice bath then vacuum filter with hirsch funnel. (The one with the built in barrier.) Not sure if this is what you are doing but that's how I always did it and I generally didn't have a problem. Could you give some more details how your lab generally does it?

 

[mshheaddoc]

We're using bruice and I'm on my 9th or 10th lecture? We're only on chp 3 now which makes me feel like we go so slow compared to you guys! 😱

But since I've already had this class once, the best advice I can give is to STAY on top of it. Do the homeworks assigned for every class. If you have questions, email your prof so he knows what to go over in class or go see your TA. I personally have two issues, electron crap (with orbitals on certain molecules) and lewis acid and bases. We have a test next friday on chp 1-4 and pretty much we were told chp 2 is on our own. Not fun but its doable. But only if you keep up with assignments.

Our school has one lab for OchemI and II which I dont need ot take till next semester. I'm NOT looking forward to repeating lab. I actually despised the smell more than analytical chem. I actually liked analytical chem lab 😳

 

[JustR]

How could you like the analytical chem.?

Actually, I did like it too, [🙂]

But the worst part about the class I took was something else, which ended up giving me the grade than what I really deserved. But our Analytic lab, we had to be so precise and accurate in reporting results with fewer errors as possible while they always gave us the contaminating reagents. Then there was no way to get 100% accurate. Class in itself was not bad, but how it was taught maybe was the problem in my case.

 

[jon stewart]

We're using bruice

how is that book?, il be using it soon. I sure hope its good.

 

[beastly115]

We're using bruice and I'm on my 9th or 10th lecture? We're only on chp 3 now which makes me feel like we go so slow compared to you guys! 😱

I use Bruice also and we've had about 2 weeks of lectures and just finished chapter 1. I don't know, maybe the chapters are bigger in the Bruice book than the other o-chem books.

The Bruice books is pretty good, imo. I haven't looked through any other o-chem textbooks so I can't really compare but so far we only finished one chapter and there was maybe 1 section (of about 20) that I didn't understand after reading it. So far, so good.

 

[DrBowtie]

Gets gritty? You mean you're getting garbage in your samples or something? I never really had that problem. Basically I just do the standard stuff. So step one triple check that I had the right solvent.(Because later on it's so damn easy to use the wrong one.) Step two put the solvent in one erlynmyer(sp?) flask and the crystals in another and heat up both flasks until the solvent is borderline boiling.(Apparently trying a regular beaker instead of an e-flask is just asking for trouble. At least that's what Zubrick talks about.) Step 3 use a clean pasteur pipette to add the solvent dropwise to the solid until everything just barely disolves.(You should see absolutely no precipitate in the solution. Usually the solution will have a color but no specs or anything like that.) Step 4 let cool to room temperature, seeding it if necessary.(And the manual probably should mention that. Not hard to do but sometimes necessary.) Finally step 5 ice bath then vacuum filter with hirsch funnel. (The one with the built in barrier.) Not sure if this is what you are doing but that's how I always did it and I generally didn't have a problem. Could you give some more details how your lab generally does it?

What you outlined is the procedure I followed. However on the microscale I used methanol as a solvent which was correct according to zubrick. I added hot methanol and it all dissolved. So I cook it down some and evaporated some liquid. I let it cool down to room temperature and put it in the ice bath. After cooling, no crystals were forming so I added DI water until the cloud point. The crystals that were forming were almost granual. (This is where I am looking for tips into getting larger crystals). So I vaccum filtered using a hirsch and the filter paper absorbed all of the really small crystals. I tried to scrap them off using a spatula but nothing that could be measurable came off.

 

[Dave_D]

What you outlined is the procedure I followed. However on the microscale I used methanol as a solvent which was correct according to zubrick. I added hot methanol and it all dissolved. So I cook it down some and evaporated some liquid. I let it cool down to room temperature and put it in the ice bath. After cooling, no crystals were forming so I added DI water until the cloud point. The crystals that were forming were almost granual. (This is where I am looking for tips into getting larger crystals). So I vaccum filtered using a hirsch and the filter paper absorbed all of the really small crystals. I tried to scrap them off using a spatula but nothing that could be measurable came off.

Hmm, well one difference I notice is that I generally never cooked anything down. Once I added just enough solvent (BTW, you got the solvent out of Zubrick? Usually our manual told us which one to use and I was very anal about keeping it straight. It's really easy to write down the wrong thing when the options are ethanol, absolute ethanol, and methanol) I'd pull it straight off the heat since I didn't want to boil off any solvent. However from what you describe it sounds like you needed to seed the solution. Kind of surprised though, we didn't see one like that until late second semester.(Also our hirsch funnels didn't require filter paper so I never used any since that would just make things harder. I just made it a point to keep my funnel clean. Double check to make sure yours requires paper.) I'm also not sure adding water was a good idea or not.(We never needed to do a recrystalization that required adding a second solvent. Washing with another liquid yes but that was later on in the experiment.)

Anyway about seeding. Certain solutions the crystals don't just jump right out and make nice crystals, they actually tend to stay in solution and make a super saturated solution.(And I have no idea what happens if you let this occur. Supposedly a messy crystalization occurs but I never let that happen.) So one trick to get things going is to make a seed crystal and put that back into the solution and then the rest of the crystals form off of it. Don't worry, it's actually easy. Step one take your spatula and make sure it's clean.(Definitely wipe it with a chem wipe.) Step 2, dip the spatula in the solution and then pull it out and let it air dry for a second.(Obviously you need a small spatula that will fit in the mouth of the e-flask.) What should happen is all the methanol will evaporate and leave behind a crystalized substance on the spatula. Now just put the spatula back in the solution, hopefully dumping the seed crystals into the solution. Generally you'll try this 2 or 3 times and finally get a seed crystal or 2 in the solution.

I'm not saying this is what your problem was but this is a technique we were taught to help crystalization start.

Do they let you go to a later lab and retry it if you want?

 

[DrBowtie]

Thanks for the tips. Never heard of the seeding.

I am sure if I wanted to I could arrange to retry but it wouldn't really make a difference since I would prolly get a different unknown. I think I just had a very bad substance. I used the criteria in Zubrick in picking a solvent. Sorry I didn't clarify. Paper on the hirsch was what the TA said and told me to add DI since I think the correct solvent was a methanol/water mixture.