O Chem lab advice

[Violagirl]

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My university has it where you take O Chem I and II lecture and then the lab with material combined for the experiments. Throughout this semester, I've had a TA that made things difficult where he would come down hard on students for not doing things right or not having a good for product. I feel like part of the reason why I was struggling was in part because of that. He apologized today to my group for how things were going and said he would work on changing things so I feel like I have a clean slate. Today we had to do a Grignard reaction and i was the only one that was unable to get the magnesium turnings to react with bromobenzene in diethyl ether along with a stir bar over a stir plate to mix it all together. I kept my apparatus free of water and held my hands around the reaction flask to keep it warm to get it going but nothing worked. Anyone have any advice on either this particular reaction or in general on how they succeeded in lab? Sorry to go off on a tangent like this but thought I'd see if there were other people here that have been in this position. 🙂

 

[circulus vitios]

That's kind of how organic chemistry lab works: you follow the procedure to the letter, and nothing works right.

 

[Amba]

What is the focus of the grading? Combined between lab reports, quizzes, and tests, at least 90% of our grade went into understanding WHY we did what we did. My tips:

* Thoroughly understand what you're doing (ex. what the point of each reactant, catalyst, solvent, etc... is)
* If you have a TA that likes to deduct points for bad yields (mine wasn't), don't be afraid to accidentally mark a number or two wrong in your notebook to help your yield (if you catch my drift)
* Learn to accept that part of orgo lab is getting weird unexplainable products. Everyone in my lab at least once ended up with a black/purple/whatever color product that was different that everyone else's. If you have the time and permission to redo the lab, go for it. If not, hope that that is your one weird product of the semester and make the best of it.

Good luck!

 

[saveourpens]

I've been on both ends of o-chem lab, as a student and a TA at the same program. If you have lab reports my suggestion would be to be as concise as possible. I took points off if I had to read through a whole bunch of garbage and I know others did too.

In terms of the lab, if you think you're doing things wrong, look at what other people are doing (correctly) and try to copy them.

 

[coyotelime]

The most important part of organic lab is to figure out exactly what your TA likes in lab reports. The bay next to mine had a TA who wanted details. Mine wanted conciseness. He also didn't care about yield as long as we understood the methods. That being said, he did give me 18/22 on my determination of unknown alcohol lab(3 week lab I completely missed the product because my NMRs were impossible to interpret haha).

I think it's definitely a rite of passage. And I feel you on the Grignard, some people in my lab had to try it 3 times before it started going. I just got lucky.

 

[MT Headed]

Today we had to do a Grignard reaction and i was the only one that was unable to get the magnesium turnings to react with bromobenzene in diethyl ether along with a stir bar over a stir plate to mix it all together. I kept my apparatus free of water and held my hands around the reaction flask to keep it warm to get it going but nothing worked. Anyone have any advice on either this particular reaction

The only thing I ever synthesized with a Grignard was fukitol.

You bring back fond memories of having my product oil out on me, futilely scratching at the sides of a beaker to get something to crystallize, and "purifying" my product by washing nine tenths of it down the drain. Good times!

In the end, the only thing that truly saved me in ochem lab was an attitude transplant. I totally mellowed out, accepted the things that I could not change, followed all instructions efficiently and to the letter, and turned in a single white flake with confidence. I also played a lot of jokes on the instructor and TA so nobody ever knew if I was being serious. The combination of lousy yields, truthful reporting, accurate calculations, superior error analysis (I had a lot to work with, lol), and a pleasant attitude was enough to bump my marginal grade into the A range. And maybe that was a life lesson far more important than learning how to successfully convert one white powder into another.

Good luck

 

[Violagirl]

Thank you all so much for your input and suggestions! I know that I have definitely improved since the semester began but it's days like today where things don't go right where it's hard to feel positive about it. I know I'll have next Tuesday to do it but I have to start from scratch and do all of the extractions and recrystallization that will go along with it and am hoping I won't screw up again.

MT Headed: Thanks sharing your experience with it! Attitude definitely makes a difference. I do try really hard to be positive about it but sometimes it gets to be overbearing. Especially if your TA seems to only get on you when mistakes come up. Not sure what it is but it sounds like people find Grignard reactions to be really tough.

 

[1TB4RKSB4CK]

My lab is a freakin' joke. My prof turns our lab into a "club" with music blasting and some people dance while doing reactions. I'm dead serious.
My lectures, on the other hand, are to be taken very seriously.

 

[saveourpens]

My lab is a freakin' joke. My prof turns our lab into a "club" with music blasting and some people dance while doing reactions. I'm dead serious.

Yeah, for my lab I think one of my titles on my syllabus should have been "DJ". I played everything from Tiesto to Lil Wayne and everything in between. I also took requests and usually judged how good the song was by noticing head nods and/or girls dancing.

Honestly, it just created a good atmosphere. You'd walk into another lab without music and it would be really boring.

 

[organdonor]

That's kind of how organic chemistry lab works: you follow the procedure to the letter, and nothing works right.

One thousand times this.

Figure out how your lab reports are graded and follow that. If they want mechanisms in the write up do them, they want you to regurgitate your notes do it, or if they just want a short little thing

Make friends with people who know what they are doing and do what they do. For goodness sake don't be the first one to do something haha. Watch someone else and learn from their mistakes.

One often overlooked thing is in the washing of glassware. If you really care about a high, pure yield and getting the right properties of your product, wash your glass like it's your job. Not just the rinsing with water and half assed scrubbing that was so prevalent in my lab so you could leave. Use soap and a brush and rinse THOROUGHLY. If your lab doesn't have a bottle of palmolive or it keeps running out, just go buy either a little one for yourself for like $.50 or you can be the good guy and buy a big one for the whole lab for a couple dollars.

 

[JonnyL]

That's kind of how organic chemistry lab works: you follow the procedure to the letter, and nothing works right.

Truth.