[movies]

This morning I was sitting in on the intro organic chemistry class that I am TAing.  Suddenly I was struck by the disparity between "paper" or "classroom" chemistry and the chemistry that we actually carry out in the lab.  For example, a simple Grignard reaction with an aldehyde is easy to draw out on paper.  However, there is quite a lot of technique involved in actually performing a Grignard reaction.  It seems that all of these subtleties are glossed over in the classroom.

So, my question is do you think students learn chemistry better in the lab or in the classroom?  I realize that both are necessary, but which is more effective?

Comments from anyone at any level are welcome!

[jdurg]

The Lab.  Humans are visually perceptive creatures and we tend to remember things better if we see them rather than just read about them.  (Hence why so many people find quantum mechanics such a pain in the ass.  You really can't 'see' what's being talked about).  Another example is when you're driving someplace.  If you are given directions with specific landmarks that you know about used to guide you, you have an easier time getting there than if someone just says 'make a right here, a left there, and another right here'.  

In a lab, you actually get to see the chemistry happening.  You can remember how you did this, then this, and that compound was formed.  In conjunction with the lecture, there's a greater chance that it will be retained.  That's why demos are CRUCIAL to the success of any general chemistry course.

[movies]

Okay, so what do you think about universities where they have a discrete lecture class and a discrete lab class.  The one lab classes covers most of the fields of chemistry (organic, inorganic, physical/analytical) but is not directly tied to the lecture portion of the class and need not be taken concurrently with any lecture classes.  

(By the way, I believe that this kind of class is what is required for an ACS accredited degree)

[Mitch]

So how do make a grinard. Do you just toss some magnesium chips with an alkylhalide in an air-free sensitive environment?

[movies]

So how do make a grinard. Do you just toss some magnesium chips with an alkylhalide in an air-free sensitive environment?

It's a little more difficult than that.  Magnesium oxidizes in air so rapidly that you have to either crush the turnings once they are in the flask and under degassed solvent or activate the surface by some chemical means (e.g. iodine or dibromoethane).  Even then you often have to heat the solution to get the oxidative addition to go.  Beyond that your glassware has to be meticulously dried and air excluded.

To a grad student or someone who does bench chemistry regularly all of this stuff is pretty routine, but for a student just starting out these subtleties are far from obvious.

[objectivist]

lab helps me understand chemistry and i learn better from it than what i learn in lecture. sometimes what  i  do in lab doesnt match with lecture, and sometimes it does.

[Donaldson Tan]

my experience of labwork at university is not great. often a time, i did the lab work before the theory was taught, so I had no idea why I am doing this and that according to the procedure given. I am just following instructions in the lab. It's only after I had done the lab work, spent some time reading up some chapters in a textbook, then I've a good idea of my lab work and often regret that I failed to improvise my experiment or had measured the wrong variables.

[hmx9123]

Regardless of the separation of lecture and lab into different courses, it's sad that lab usually doesn't have the prominence of lecture either in credit hours or in 'importance' as alluded to by most instructors.  As geodome stated, I think it's pretty common experience to have students do a lab out of sync with their lecture, thus really questioning the entire relevance of it.  My experience was even worse--the lab instructor didn't communicate with the lecture instructor and the two courses had nothing to do with one another content wise.

That being said, I personally like lab more.  I tend to think for most students the lab simply reinforces the lecture material, so they should be taught together.  However, for chem majors whose line of work it is to do research, I think the lab definitely is more important and needs a lot more prominence.  Out of all the labs that I've seen, one was fantastic.  Dr. Don DeCoste (U of Illinois) does a fantastic job with labs by using an innovative approach--he gives no procedure for how to do something.  He gives the students a list of reagents they can use and presents them with a problem: how to accomplish a certain reaction, how to measure something, or how to test a hypothesis.  It's up to the students how to do it.  They then present their procedures to Don, who gives them the go ahead or helps them to revise it and gives them more questions to think about.  I really like this idea, because it makes the students really take ownership of their procedures, not just read through it and wonder what the hell they're doing.  When you think about it, that's what research is: you try and figure out how to solve a problem, then you have to do literature searches and come up with your own procedure.  Obviously, in the interest of time, the lecture relates closely to what's going on in lab, and the choice of reagents is pretty limited, so they can't come up with some really crazy stuff, but it is still very much a thinking process.

[Donaldson Tan]

Dr. Don DeCoste (U of Illinois) does a fantastic job with labs by using an innovative approach--he gives no procedure for how to do something.  He gives the students a list of reagents they can use and presents them with a problem: how to accomplish a certain reaction, how to measure something, or how to test a hypothesis.  It's up to the students how to do it.  They then present their procedures to Don, who gives them the go ahead or helps them to revise it and gives them more questions to think about . it is still very much a thinking process.

LOL. That's what I do for my pilot plant study. That's why I enjoy it tremendously as well.

[NandhiniReddy]

 i think both lab and classes are necessary. taking a class in lab and showing the students practically whatever is taken, will be useful

[xiankai]

i often find lab lessons very fun, except for the fact i dont really know what im doing.

i just follow instructions, and am expected to give certain answers. it can be very satisfying to see how chemistry works out in real life applications, because thats what chemistry is about. but the problem is most of the time we are jsut asked to indentify only certain properties of the reagents, and in the end we are still in the dark about what the reagent is. the point of lab was to reinforce the analytical chemistry skills.

i always end up feeling that i left out something... due to half of the time spent explaining what to expect and the other half of the time actually doing the experiment.

on a side note, i once obtained a milky white mixture after adding sodium thiosulfate o_O can anyone enlighten me what it was, everyone else got a different colour.

[Rayan]

i enjoy the lab a lot more than lectures. but i also dont know what i'm doing, i just follow instructions.. and now that the lab sessions are over, when i think about what i learned, it is mainly about how carrying experiments and some really general properties of material.. it's like i know we use charcoal to remove colored impurities, but i learned nothing like reaction mechanismes or stuff like that.. although lectures are very important, i still enjoy lab more!

[Benzene265]

You need them both.  If you're doing reactions, you don't always have the time to take notes on the mechanism.  In lab, you make observations and make sure whatever you're making doesn't blow up on you.  Then you have to stand in line and wait for various spectrophotometirc equipment to analyze your white powder or clear liquid.  I'm sure there's time to discuss theory there, but the labs at my school are in the afternoons and no one's interested in hearing another lecture.  So, hopefully the section on making carboxylic acids was covered already in lecture, or will be soon.


I like it best when the same professor is doing lecture and lab.  Then, they tend to synch perfectly.

[TakeItEasy]

Both of them are necessary...classroom and lab are like body and it's organs without either they will not function well.

[Qazzian]

Both.

The lectures and labs should compliment each other. In addition to learning how you do certain lab tasks, you need to understand the theory behind it, and how it can be made general.

Sure, it's great to know how to add Bromo-benzene to Formaldehyde, but what about later when you need to synthesis something different. There's no way to cover EVERYTHING in the lab, so you need to know the theory. Teaching the theory in a lab is quite stupid, because it's a waste of space and resources to draw mechanisms and to teach about reaction types when you could be doing it on paper in a lecture hall much easier, with more people.

At the same time, knowing the theory isn't enough, as the reactions themselves help r-enforce things. I know I wish I had a lab section with my biochem course I'm taking, as alot of it was "here's how you'd do something in the lab, but we're going to jut talk about it, but you would do this". Actually purifying proteins would be much better, since it'll help with our understanding.