Curved Arrow Press news

Another curved arrow example

P. Wepplo — 2009-11-04T11:28:01-05:00

Okay, so I have my book on the market and the people I really need to adopt it are people that teach organic chemistry. However, that is proving a challenge. If you read back to some of my earlier posts, you will find that one objective I had in writing my book was to eliminate ambiguity and confusion. Below is something I found on the internet. It was about SN1 v E1 reactions. ...… I just lectured on beta branching this morning, and neopentyl electrophiles react some 100,000 times slower than ethyl bromide in SN2 reactions. So if you let it go long enough, yeah, you'd probably get some SN2... eventually. So I predict one of the rare cases where rearrangement and LG expusion occur simultaneously. This gives the stable tertiary carbocation. We're in good base, so E1 elimination should occur after carbocation formation. … My sketch of the arrow-pushing is below. Let’s look at this again, “I just lectured on ….” So, this is someone that teaches organic chemistry. Let’s look at the curved arrows used by this person. Okay with the first set, that means rearrangement. Let’s look at the middle set. That looks like a second rearrangement, doesn’t it? This was my point. If I was a student in this class, would I pay attention to the curved arrows or would I just ignore them? There is not anything particularly wrong with the curved arrows in this instance except they are bordering on ambiguity. I only say it is bordering on ambiguity as the pair of electrons from the (-)OH implies a bond change for the C-H. The middle set of curved arrows should have pointed to between the atoms to indicate a change in bond order. Let’s review the curved arrows with how they might have been written. I have tried to be more careful so that a curved arrow starts with a pair of electrons and ends between the atoms to change the bond order to a double bond. You may also notice that the original curved arrow in the middle set appears as though it is being used to break a bond, like the example below. For this reason, I had adopted a more unambiguous way of using curved arrows, see below with the same example.

Publishing 101 or setting the price for the book

P. Wepplo — 2009-01-27T01:27:55-05:00

I am setting up a new price for A Guide to Organic Chemistry Mechanisms. The book hasn’t been selling very well and there are other books mechanism books that are less. ...Initially, I was selling the book for $25 and I was getting it printed and bound at Staples in small volumes. While that was useful to make a few sales, I wasn’t making much money from the book. ... (Yep, I don’t go there any longer--I had a reasonable estimate and when I went to pick up my order, they said there was an error.) As I progressed, I improved the production by printing them on my duplex laser printer. I am not sure what the price was for those as I would have to determine the number of books I produced, the binding charges and the supplies, including cartridges. This was better, but I knew the deal that Amazon specifies on their website. There is an annual fee of $29.95 to be a member of Advantage. Your fee includes unlimited title enrollment, access to our Vendor Services team, and access to the Vendor web site to manage your account. The standard terms for Advantage vendors is 55% - you keep 45% of the List Price. That means that Amazon.com is entitled to 55% of the List Price for each unit that sells. You, the vendor, receive 45% of the List Price. You set the List Price, also known as Suggested Retail Price, of your products, and all payments made to you are calculated based on the List Price. If Amazon.com decides to further reduce the sales price to the customer below the List Price, the customer discount comes out of Amazon.com's percentage. ... If I am charging $25 and my cut to print and ship the book is $11, obviously, I won’t make any money if Amazon sells the book. ...When I do this, there is a default publishers discount that “I can set”. ... Well, I am not going to sell any books from my website if Amazon is selling them for $20 less. Why did I raise the price if no one is going to charge that amount. ...However, what I didn’t know was that he did not have an agreement with Amazon. ... I succeed in getting Amazon’s price up to the retail price, but this really slows sales. I have set a new price for my book at a more reasonable $34.95 and chose a discount that I hope will place my book at a more favorable price with its competitors. In setting the price, I wondered why Amazon had not changed their price. I find a note with my printer that my cover must be changed as well because a price code had been embedded in the book. I complete the change, upload the new cover with the new price, pay my $40 and I’ll wait for the changes to show up and see what effect they will have. I am sure there would be others smiling now because they know everything that I am slowly learning.

How to learn ochem

P. Wepplo — 2009-01-15T12:42:13-05:00

I am gathering data on how students learn ochem. I believe a common method is simple pattern matching. It is easy to do and doesn't require great effort. The problem develops as the matrix of answers grows beyond a certain level. It is at this point that I often heard, "I am so lost". That is, the students are saying there are more answers than they can connect simply by memory. There is a solution to this, logic. Our brains can connect information together if it is based upon earlier principles. Such a method of thinking is logic. Reading and writing is constructed in this way. If you needed to learn the Gettysburg address, you would know this. You would know this because if I gave it to you in another language, it would either be much much harder or impossible depending on the similarity to a language you already knew. The intellectual connection is that the phrases create meaning, the words create phrases, the letters create words, and the shapes create letters. If you didn't know Chinese, and I asked you to learn the Gettysburg address in Chinese, it would be impossible because no logic for connecting the shapes would exist. It would be like trying to draw a Jackson Pollack painting from memory. The chemical equivalent of logic is reaction mechanisms. Students would ask me how many mechanisms did they need to know. I would answer only the number that you wish to answer on the exams. I have not found this to be a problem as reaction mechanisms are constructed on similarity to other mechanisms. It never happens that you would learn one mechanism that did not rely on principles you had learned earlier (Markovnikov addition is a family of similar reactions). You can read how students have done in my classes on my website. Disclaimer, I am the author of "A Guide to Organic Chemistry Mechanisms" (Amazon.com, Barnes and Noble or http://www.curvedarrowpress.com ).

Learn OChem w/o taking a class

P. Wepplo — 2008-11-29T22:40:36-05:00

This is interesting as I was just thinking about how organic chemistry is really about electrons and their movement. Even at this time, with all that we know, I remain skeptical of what we really know and my ability to change this knowledge. I am reminded of the parable of the blind men and the elephant. ...

And so these men of Indostan ...

Though each was partly in the right,

And prate about an Elephant

So what exactly do you do as a Organic Chemist?

P. Wepplo — 2009-10-16T10:04:59-04:00

I had a wonderful career as an organic chemist working in industry. There are many areas of organic chemistry and "using natural products" is probably a minor one. Let me qualify that. In the area of small molecule chemistry, there is a relationship between the receptors of the natural products and their regulation by natural products themselves. However, the nature of natural products can limit their affinity, lipophilicity, and metabolic properties. I will guess that solving those problems, whether structurally related to the original natural products or not, is the bulk of organic chemical research. Whoops, left out a big one here. Creating an economical synthesis of any small molecule is also of great interest and research. Is this for you? Jason Reitman has been interviewed several times with his movie "Juno" being nominated for an Academy Award. A quote I loved was something he heard from his father (and grandfather). He was considering going to medical school. His father said, "I don't think there's enough magic in it for you." Of the people I know that love organic chemistry, I think what they love about it is the "magic".

Why is organic chemistry so difficult?

P. Wepplo — 2008-10-02T18:12:20-04:00

For some professors, it is difficult simply because they want it to be difficult. For those professors, it is difficult to know how to prepare. I have written several blogs on my website about learning and organic chemistry (www.curvedarrowpress.com). ... However, I detect some differences in expectations from what I did in my classes. ... This sounds as though you studied the vocabulary words for French class and the actual questions are in German. In my experience, it is difficult to imagine questions about chemistry that are not in a book. Oh, they may look different, but the principles are generally quite simple and basic. ...Learning organic chemistry is not memorization of facts. ... You need to learn the principles to be applied to a problem. Here, organic chemistry is more of a language than a collection of facts. If a computer is programed with English translations from an original language, what comes out is unintelligible or barely intelligible results. ... In organic chemistry, your objective is to connect the facts or problems with the rules or principles. In my teaching, I had begun to note that the top students rarely used flash cards. I had posted a correspondence with a student who was wishing to make lists of chemicals. While I did not think he should not do this, I also did not think it would help him to know something he did not. ... Listing together a group of chemicals (nucleophiles) that you did not know would not be as valuable as knowing what they did in the first place. That is, it occurs to me that a list of nucleophiles will not teach you which are nucleophiles as effectively as learning how nucleophiles react and deduce what they had in common. That is, it is easier to label a compound as a nucleophile because of how it reacts than it is to learn how to use a compound because it is in a list. I have done very well with students who have legitimate expectations of going to medical school. If having organic chemistry making logical sense is appealing to you, then I suggest you consider the book "A Guide to Organic Chemistry Mechanisms". The book is a guided inquiry workbook that is designed to teach you organic chemistry reaction mechanisms, the 900 lb gorilla of organic chemistry. I have had excellent success with the book, especially with students of above average ability. Learn reaction mechanisms with "A Guide to Organic Chemistry Mechanisms©" now available at Amazon.com, Barnes and Noble or http://www.curvedarrowpress.com . ...From the webpage … "In class, I began to expect that students who used flash cards would score lower than those that just learned mechanisms. Flash cards may be fast and easy, but they didn't follow my thinking of how our brains learn the language of organic chemistry. ...What I don't know about your class is whether your instructor waters down mechanisms and reactions.

How I improved my class performance in organic chemistry

P. Wepplo — 2008-09-20T13:56:37-04:00

I have no doubt these quizzes and exams were not popular with the students, however I knew that if I wished to have the best possible scores, I needed to have the students practice solving problems (thinking organic chemistry) as much as possible. ...Even though I provided mechanisms in class, I found few students could solve problems by writing complete reaction mechanisms. ...I began by using the exact problems that were included in the homework on the quizzes. ... My first change was to begin to give those problems as part of the homework and I would use some of those problems on the quizzes. ...I advised them that these exact problems would be on the exam and that they should know them. Furthermore, I advised them that since I had given the solutions before the exam, I would grade them more harshly. ...The student would be happy because they would know the answers to the problems and I would be happy as students would know the reaction mechanisms. ... While I could have guessed that superficially, students were unwilling to study enough to learn the mechanisms, I surmised that many of the students did not comprehend the logic of the mechanisms and were thus unable to write them from memory. An analogy I suggest is that if you had to memorize the Gettysburg Address, it would become increasingly difficult if the language of the address is changed from English to another Romance language or finally to Chinese. ... This is why I believe many of the students did so poorly and I discussed this result at an ACS meeting. ...By doing so, students could first learn the logic of the reactions and then by repeating that problem with more information removed, they could build on that simpler version. ... Those worksheets were adapted into the book A Guide to Organic Chemistry Mechanisms (originally titled The Language of Organic Chemistry). ...The simple could be answered simply by virtue of having read an assignment while reaction mechanisms may have been discussed in class or present on a prior quiz. ... I also used problems that were assigned from Organic Chemistry by Paula Bruice. ...While I was transitioning my class to mechanistic thinking, I had not made a total commitment to it. ... Since students had a solutions manual for the textbook problems, they did could determine the product without using a mechanisms. That was my objective in writing the supplemental problems, to have problems that were similar to the textbook problems but which students had to figure out (mechanistically). ...After the exam in which the mechanism problems were given before the exam, I began to change the supplemental problems. Since I was handing out mechanism worksheets, I began to write problems that used the worksheet mechanisms and to ask for mechanisms on the quizzes. Over time, I continued to increase the number of supplemental problems and ask for more and more mechanisms. Since I had collated the worksheets into a workbook, I was able to better coordinate the material from the textbook, the workbook, and the supplemental problems. ...Since my questions now focussed more on how the product formed and not what will be the product, giving the product to reactions would help the students. ... Therefore, by virtue of asking students to write mechanisms for problems, students were better able to write mechanisms because they could arrive at the correct product. ...I would like to summarize my interpretation of the salient points of my teaching that I think contributed to the percentile increase on the ACS exam. First of all, the ACS exam focusses on the fundamental aspects of organic chemistry that mechanisms are well suited to answer. ... I continued to give five mechanism questions (out of 5-8) on my exams and I announced them before the exam.

Science and scientific thinking

P. Wepplo — 2008-04-03T11:46:13-04:00

Science is a process, not a collection of facts … Yet, if you have the process, you have the ability to eventually understand the facts. ...While he is correct in his view that scientific thinking it not different from regular thinking, one must be careful in how the terms are used. ... When one talks about chemistry or physics, they are talking about the facts, not how those facts came to be. For example, a discussion of gravity is a reference to the phenomena by which an object, if lifted from the surface of the earth and released, will fall back to the surface of the earth. ... If you were to ask the ‘man on the street’ to determine the velocity of the object when it hit the ground, he might reply, “Oh, I am not good at science.” What he means is that he lacks the skills necessary to do the calculation or to use the mathematical formula to determine what data he needs to acquire and then make use of it for the calculation. ...What we don’t (and ‘the man on the street’ doesn’t) know is what diligence and time it would take to get them. ...Scientific thinking is how we view the world, what certainty it has, and how we might predict its future. ... Ironically, considering ALL possibilities (even ones we think are not possible) can be a great asset to scientific breakthroughs (science in the usual meaning). When I taught a general science course, I likened scientific thinking to regular thinking with the corresponding words. ... When we think of scientific facts, the difference between regular facts is that arguments of science are such that anyone who observed the same facts would come to the same conclusion. ... Two people can look at a set of facts and rationally come to different conclusion based upon their religious beliefs. ...Bad things will befall those who lead bad lives, that is, the gods are monitoring behavior and punishing those who violate their rules. When we talk about a scientific law (or something we know), we mean the patterns are so certain, that everyone would agree to the likely outcome of the prediction. What we do in science is to transfer or substitute one example for another that is believed to represent the same pattern. ... That is, if you were to add two balls to a basket with two balls, the basket would not contain four balls. ... It is science because everyone would anticipate the number of balls that would be present in the basket. ... My dog can anticipate clues for being fed or to do a trick, but he cannot grasp arithmetic. What makes science difficult (classical science) is the proofs and abstractions that it may use are very complex. ...For me, the disappointing aspect of this argument is that it seems easy to apply scientific thinking but we are surprising unwilling to do so. ... Logically (this is a kind of thinking pattern), that also means that humanity’s predecessors were not aware of the same rules of heredity. Those who described how the world might have begun would not have the knowledge of DNA, a genetic code, and properties of inheritance. However, the possibilities are simple, either our genes are fixed (and were created at some primeval event) or they are not. ... How can a sizable portion of the US population (including our president and presidential candidates) think our genes are fixed? ... Should we be fearful of the Afghannies attacking our country if we lost the war (as though winning was a thing, like a race)? ... Is the mortgage crisis a real crisis or a result of a weak economy and a shift of wealth away from those wishing and able to buy homes?

Organic chemistry help?

P. Wepplo — 2008-03-13T01:57:47-04:00

I have a question about organic chemistry (Ph D please answer it)

I really like organic chemistry 1, but I do below average on all the tests and quizzes. I read the book, do problems, but then on the tests the questions are so different. It's like what the professor teaches in class is not useful for the exams. ... (I go to see the T.A., but again as I said before, the exams are completely different from class material) ...It is difficult to predict the results precisely because I see a wide variety of approaches and concentration to organic chemistry. Some professors teach organic chemistry-lite and some have questions that are very challenging. ...While the following topics are not universally easy for everyone, nomenclature, stereochemistry, conformations, diastereomers, etc., are static in nature and most students master them without great difficulty. ...Some professors emphasize them and require students to write them, others try to mitigate their impact on the overall grade. ... If the exams concentrate on the mechanisms, then you need to learn the mechanisms. If the exams are multiple choice and the questions resemble the prior years, they allow a kind of superficial pattern matching - organic chemistry-lite. That is like learning the 20 most popular phrases when you travel to a foreign country and to think you speak the language because you are using the words used most often. I think learning organic chemistry is very much like learning a foreign language. If you want to be fluent, you need to know the meanings of all of the words you are using. The more words you know, the more you can learn, in context. (Did you ever see a baby look a word up in a dictionary? They learn their entire language in context.) My experience is that if a student understands reaction mechanisms, it gives them the most ability to solve a variety of reactions, including using reagents and reactants they have never seen before. ...I am planning on giving a talk on how I was able to raise my class average by 20 percentile points on the ACS organic exam. I can tell you that what I did was to concentrate on reaction mechanisms and how I made them understandable to the entire class. Because my teaching was quite different, I believe students did a lot more learning in class. My class had less of the talking-note taking and more learning in class. You can learn more about the book I wrote for the class, "The Language of Organic Chemistry; A Guide to Organic Chemistry Mechanisms" at http://www.curvedarrowpress.com . If you look at the book, you can see that you can learn organic chemistry without my help. However, it is difficult to predict how effective the book can be for you and your class if your professor isn't using it. I do hear back from many students how effective it has been for them.

What is a good book for learning organic chemistry?

P. Wepplo — 2008-03-13T01:54:15-04:00

I have "Organic Chemistry Demystified" but the topics seem out of order and all over the place and the explanations very elementary. I understand the subject but would prefer something that sums up major points. My reply, You could look at my book, "The Language of Organic Chemistry; A Guide to Organic Chemistry Mechanisms" at http://www.curvedarrowpress.com . I can't say it would be for you or not. When students turn to Made Easy, for Dummies, Demystified, that is not a good sign. I have looked at them. They seem to be like a Reader's Digest version of organic chemistry. I have not thought that any of them gave a more clear explanation than you would find anywhere else, just shorter or skipping a lot of details. In my classes, I focussed far more on mechanisms than the introductory subjects that some students worry about. I learned most students would be able to name enough compounds if just given enough practice over the course. I did not pack it in early, but I just kept using examples throughout the course. Many terms and static things, I treated similarly, conformation and stereochemistry, for example. However, reactions are the 900 lb gorilla that I concentrated on. Answering student questions, scanning different books, and reading professor's exams, tells me there is a good deal of variation in the importance of mechanisms. For anyone really wishing to learn organic chemistry, I would suggest they learn the mechanisms, even if your professor does not emphasize it. I learned more chemistry from mechanisms than any other way. In fact, a mechanism is just an proposed explanation of how a reaction takes place. I tend to extend this in ways students may not. When an alkene reacts with an electrophile, I don't think the electrons of the alkene react any differently in one reaction than another. Therefore all of my mechanisms follow very similar motifs. Because learning is pattern matching (that is what out brains are good at), I am therefore making it easier for you to anticipate how a reaction will occur (because you are going to repeat a pattern that I am repeating). I don't know the teaching philosophy of your professor. If he is dedicated to terms, form, and format, then I don't think I can help you. If you like things to make logical sense, then you may like my book.

eBook version of "A Guide to Organic Chemistry Mechanisms"

P. Wepplo — 2008-02-20T10:23:28-05:00

The ebook version is available until June 1, 2008 and at no cost. I am also going to put up Chapter 8 as a demo chapter with all of the parts. Donations will be gladly accepted. ...I have been working hard at updating a number of aspects of "A Guide to Organic Chemistry Mechanisms". One objective was to again sell an ebook version of it. I searched for various methods that would allow good access and little maintenance. The use of the Adobe Document Center was problematic with the setting up individual accounts, providing access, verifying, client logging in, and problems with the process. Furthermore, it wasn't within the Adobe terms and conditions. I am experimenting with another option. A number of people are visiting my site, looking at the mechanisms that are available, but not making a purchase. I am going to provide a short term access with a very low cost. This can be renewed or an outright semester long access purchased at a still modest $9.99. I have compromised on the ebook by eliminating Parts A, B, and C. In the past, few students that purchased an ebook actually printed out any pages. I have concluded they are more interested in the completed mechanisms than the process of learning the mechanisms that the complete book provides. This also makes the ebook more streamlined. You can open it and scroll from top to bottom or click on the bookmarks to jump from chapter to chapter. I can see much potential in an ebook version. There are a lot of searchable terms present in the book. I hope to discover a **find** procedure for this (if I can find one). I can also foresee that the ebook format can develop into a virtual lecture on reaction mechanisms. However, those are items still in the future. This should give greater access to the book. I have retained the pre-bonds that make the mechanisms unambiguous. If you find that you wish to upgrade, I will credit any prior payments to the full semester version or a print version of the book. I would encourage anyone wishing to learn the mechanisms to purchase the printed version and work your way though the mechanisms.

How to use Spotlight without searching the trash

P. Wepplo — 2008-02-03T15:16:42-05:00

I was looking for how to remove the trash folder from my searches. I found there were trick to exclude it including first going into terminal and ... That didn't look too appealing. I saw in one of the searches a description of how to use Boolean logic in Spotlight. Well, well, well. I think I will try that to exclude trash. Voila, that works like a champ. So if you want to search for "something" and want to exclude "something" that is in the trash, try this, "something(-trash)". It seems to work for me.

Free Lunch: How the Wealthiest Americans... David Cay Johnston

P. Wepplo — 2008-01-30T10:15:20-05:00

If we use Steve Jobs as a model, I can admire his contribution to his wealth, but there is a limit. ... If Apple corporation financially stumbles, whose career is at greater risk the engineer, the janitor or Jobs? ...The assets of a janitor will be limited to what he can earn through the largess of his employer. A bank robber can take advantage of someone else's labor and expand his assets beyond his own effort. So, if I wish to have that monument built (Apple Corp), then should I applaud Jobs because rather than a gun, he was a friendly embezzler? ...The bank robber, if he is nice, can do what I cannot. At the turn of the century, no income tax existed and workers did not think they got a fair share for their labors. As a result, labor unions were born to balance the exchange between business and workers. As I look at the world, it occurs to me that taxes are simply a tool for social equality. ... • Bank robber: someone who takes your cash at gun point and leaves nothing • Embezzler: someone who takes your cash without a gun and leaves nothing • Swindler: someone who uses your naivete or avarice to take your cash without a gun and leaves nothing ... • Grocer: you (also known as someone who works his butt off and gets nothing) ... • Illegal immigrant: no gun, no cash, no tools, no home, no one on his side, and no future ... • Successful businessman: cannot keep count of the tools he has, he is rich • Middle manager or scientist: no tools, but works for businessman, middle class • Tool: what businesses need to do the work, tools cannot cost more than they can produce • Politician: like a pro athlete, works for the rich (or may be rich) to keep populace in check without the entertainment value ... • Apple fanboy: referred to by Lincoln on fools, "some of the people all of the time" (you choose whether Abe meant M$ or Apple) ...I am thankful for the taxes I pay for I too have taxed those beneath me (vicariously). All I ask is that everyone else whose earnings come directly and indirectly from the labor of others would take that same charitable view. I don't want to be in the business of trying to determine whether wealth was obtained as a robber, an embezzler, a swindler, or a legitimate businessman. I just ask that if you recognize that your wealth came from the work of others. Taxes are the gentile device that society has to try to balance power and wealth. ...If a greater proportion is paid by the wealthy, then that shows how far out of balance the wealth has shifted. Had they not skimmed their way to the top, the less they would need to pay.

What topics are covered in an organic chemistry college course?

P. Wepplo — 2008-01-24T14:00:12-05:00

What topics are covered in an organic chemistry college course? I keep hearing nightmare stories about how hard this course is so I've convinced myself that I need to study independently a semester in advance so I won't feel too overwhelmed when I eventually take it. I bought a cheap ochem textbook (and ochem for dummies to supplement) but I'm not sure what parts I should read in the textbook, unless most courses require that you read the book from beginning to end! (which in that case, might be a good idea to start reading now!) oh yea, if possible, can you specify which ones are in ochem-I and ochem-II? I am very grateful for your answers. ...I can't speak for your school, but the course and expectations can vary quite widely. From my experience, most students succeed with stereochemistry, conformational analysis, nomenclature, etc. ... If given enough practice, students know what sp3 or axial mean. Reactions are a different matter. You start with something and end up with something else and the variations are endless. I used reaction mechanisms or mechanistic thinking as a staple of my teaching activities. I also introduced a mechanism workbook to supplement the class. By doing so, I raised my class average on the ACS organic exam by 20 percentile points. Many students (and professors) resist a mechanism approach. A mechanisms is a logical explanation of the electron movements that lead to the products. I like it. That kind of thinking appeals to me and has worked well with my class. Learn reaction mechanisms with "A Guide to Organic Chemistry Mechanisms" at http://www.curvedarrowpress.com. Incidentally, I had a summer high school student learning reactions from the book without taking organic chemistry. The book makes the reactions accessible and I believe my results are a reflection of that. At the other extreme, some schools emphasize retrosynthesis and can be rigid in how it is formatted. I have tutored some students in schools like that. I mention this because it strikes me as being extremely challenging to try to make use of reactions you did not know. It is like translating from English with a foreign language dictionary. I would expect organic chemistry to be extremely challenging at those schools.

Boiling chips, sticks and stones

P. Wepplo — 2008-01-28T13:49:14-05:00

At the surface of a liquid, the liquid phase will be in equilibrium with a gas phase. Because energy is exchanged in changing phases, excess heat is removed by changing phases. This prevents a liquid like water from being heated beyond its boiling point. If you heat a liquid and the heat is trapped away from a gas surface, the liquid can be superheated, it will contain more heat (energy) than needed to enter the gas phase. If all of the surrounding molecules are also in the liquid phase, there is no release for the energy. If too much heat is trapped in the liquid phase and a gas bubble forms, the conversion to the gas phase can be explosive. That is why bumping occurs. A boiling stone or stick simply has air entrapped within. It is porous. If you heat a boiling stone, the gas will expand and be given off. If this gas meets superheated liquid, the liquid can equilibrate between the gas and liquid phase, boiling results. You must be careful with using a boiling stone or stick. If heated too long, all of the entrapped gas will become lost and become ineffective. The other and more frequent problem is if you heat something up, and then let it cool, the gas contracts and pulls the liquid in. This can effectively block the further release of gas. Anytime you let a liquid cool from boiling to RT, add a new boiling chip as the one in the flask will be dead. You don't need to use boiling chips. You can use an ebulator to introduce nitrogen or just stir the flask vigorously to bring the heated liquid to the gas-liquid interface. I like the latter method and when distilling, I used a magnetic stir bar and stirred it at the maximum rate I could with the stirrer. Some people use additional teflon chips with this later method, but I did not like fishing them back out.

Flash Cards

P. Wepplo — 2008-01-17T14:58:23-05:00

Flash cards are such a popular device for learning organic chemistry. Why don't I like them? I have been trying to think how I can conceptualize my negativity to them. After all, I used them to learn German in high school, what is different? Lets try these examples: 4356 ÷ 363 = 12
3185 ÷ 245 = 13
20916 ÷ 747 = 18 I do not doubt that you could make flash cards and memorize these examples. These are simple examples of long division and you could easily memorize them. This is my question, "Have you learned long division by memorizing the results?" Of course not, then why would you use flash cards for organic chemistry? The key to learning long division is the process in between the problem and the answers. It is the same with organic chemistry. Memorizing the products for reactants does not teach you the process by which they form.

Nick Kim Cartoon and Chemistry

P. Wepplo — 2008-01-15T13:04:18-05:00

I was surfing the internet on some chemistry topic and came across this Nick Kim cartoon. What I like about it is that this is widely believed true, yet seems paradoxically false. If sodium cannot hold its last valence electron, then why should it be attracted to the electrons of a chloride or fluoride?

<h4>OrgoCards: Organic Chemistry Review; by Wang, Razani, Lee, Wu, and Berkowitz</h4>

P. Wepplo — 2008-01-06T12:17:20-05:00

What don't I like about flash cards? I think they cater to a concept of "there is an easier way to learn organic chemistry." A mathematical equivalent would be 674 x 328 = 221,072. Now, lets expand this to five additional examples. All would contain the correct answers. If you memorized these math facts, you could give the correct answers. Lets look to see what you have accomplished pedagogically. Flash cards associate two facts, the multipliers with the products. Now that you have memorized these math facts, are you now able to give the answer to 677 x 432 = ?. If the six multiplication examples you memorized encompassed 99% of multiplication problems, then it wouldn't matter that there could exist problems that you couldn't solve, because they would be rare. For multiplication, that is absurd. The way to learn multiplication is to learn how to PERFORM the steps in multiplying numbers together. You should not and could not memorize enough math facts to cover all of the examples in an effort to avoid the process of solving the problem using long-hand. Organic chemistry is like multiplication. Flash cards encourage connecting the start and end together without a middle. The middle is the explanation of why the reactions take place. If you look at the examples in "The Language of Organic Chemistry, A Guide to Organic Chemistry Mechanisms"®, the emphasis is on the process in the middle. It is like learning multi-column multiplication or long division. However, it is broken down and presented in a way that you can master, see Example 1 or Example 2. This is a screen shot from an excerpt of an OrgoCard on Amazon.com®. My question is, "How will this format improve your organic chemistry thinking?" It is the SAME MATERIAL, the same content as a conventional textbook. If you didn't know it or remember it, why should a flash card be better? Also, there are free organic chemistry flash card sites, like the one at OSU.

How to Learn Organic Chemistry

P. Wepplo — 2007-12-20T09:53:00-05:00

Actually, the class had the option of using the book we used for orgChem I or getting the newly adopted bruice, 5th ed. ... I'd like to think that the professor is simply using more examples and/or test bank material from the bruice book, as I am not faring as well as I would like on his quizzes. ...When I look at the struggles students have, it is the struggle to get students to attempt to learn mechanisms (and this was also the struggle in my teaching). While this would probably be far from your instructors teaching philosophy, I wrote supplemental problems that I also used in my quizzes. ... As a result, my class average more than doubled in the time that I changed to Bruice and I had introduced my book into the class. ...If you are using Bruice in your class, I can tell you which problems from TLOC will match the chapters. ...while I plan to master all mechanisms necessary to understand the orgChem reactions we are studying, what I currently need help with are chapters 16-18 in bruice, 5th ed. ...I don't know how much you know, but past experience tells me you are or may be learning the reactions for the first time. You probably pattern matched to products before, and now the problems are getting a lot more difficult and that doesn't work. This seems simple to me, but if a chapter is on additions to a carbonyl group, that is the very first step in all of the reactions. ...Paula Bruice has such a list in her book, but I can't say whether it is a valued exercise. ...If you were to ask which effort would bring a greater likelihood of success, knowing whether a given reagent will attack or to memorize reactants and products versus knowing how a reaction takes place, I'd argue knowing how a reaction takes place is more valuable. If you were to substitute another reagent in place of the one you memorized, I don't know if you would know what the product would be because the problem has changed. If you know how the reaction takes place, then you will have some mechanistic expectation of the new reagent. ...Flash cards may be fast and easy, but they didn't follow my thinking of how our brains learn the language of organic chemistry. ... You might be able to memorize the first line and the last line in Swahili, but if someone asked you to explain what either line meant in Swahili, I'd say you would be out of luck. ...What I don't know about your class is whether your instructor waters down mechanisms and reactions. ...That probably wasn't as good as just walking around the class and asking the students to fill them in. ... now, it seems sort of silly that I had such a hard time with these at all. during breaks at work and over lunch, I have just been writing them out .... doing practice problems ... reviewing mistakes, which are not as frequent now ... writing them out again ... practice problems, etc. ...What I did not think of was that when I deleted all of my email messages upon leaving the university was that I thought I had them safely stored on my home computer. ... I am sure the improved performance I enjoyed was due primarily to your text AND heeding your encouragement to actually write the mechanisms out instead of trying to memorize the reactants, products, etc. ...So you went into the exam with knowing how reactions take place and voila, you could predict the product with that knowledge. ... I believe the practice I had in using your book really helped with my overall understanding of organic chemistry mechanisms. ...It seems obvious to me that you should be able to solve at least one example of a problem to solve another similar problem, but it is difficult to get students to follow that advice, especially in my absence. ... I have less knowledge of how students do in other classes, so I am pleased to learn of your results.

Chemical Heresy

P. Wepplo — 2007-03-21T11:53:01-04:00

A crocus peaking through the snow after our
late season snowstorm (for NJ) Princeton, NJ

I have taken a momentary side track from editing "The Language of Organic Chemistry". I have created a presentation in which I have written out my thoughts on how atomic structure exists and reactions work. My next objective is to find an audience for it. It would be useful to have someone who is both critical and yet open-minded. I am interested in receiving criticism, especially where I may not have thought of something but it would be also useful for the critic to understand my arguments. After all, it is easy to criticize someone or something for being new or different. ... While they too can be useful, they are less useful to me at this point. I do not look forward to arguing one point endlessly because I am unable to convince someone that a new idea might have merit. Especially since part of my objective is to learn where my arguments might be weak and how or where to improve them. So far, I am reasonably satisfied with the overall arguments and I hope to see how they may be received. I believe it fits most reactions and principles that I can think of. I can see how the ideas may be tested mathematically, though probably not by me, although I could change my mind. Several points could be fleshed out in greater detail, but I sense this presentation is already lengthy and adding more slides would only try anyone's patience. ...I have a list of changes that I wanted to make. It is easy enough to find them and to make them. What is problematic is where to make them. Where have I made them already and where do I need to make them? It is time to become more scientific about this and to record what I have done in my notebook. I need to divide this project up into "to do" list items. Which part was I working on, what changes have I made, what ad hoc changes am I making and where have I made them? Some changes that I have made or planned, may be abandoned. I have a trial version of InDesign, but I think there is only one more week that it will be working. ... The next version of InDesign, Photoshop, Acrobat, etc., has not been released. I have seen Adobe is rumored to be preparing to release their Universal versions of the software that can be used on the Intel Macs. I also see Apple is getting ready to release OS X 10.5 (Leopard). ... I don't know that I can wait that long as these products still are not in the immediate future.