The Chemportal

I plan on doing a series where I extrapolate upon some concepts that are introduced in general chemistry, or rather explain the basis for them, in a broadly summarized terms of physical chemistry....with the aid of my Atkins companion of course.

When I first came into my physical chemistry course, I was pretty excited about the prospect of getting to know exactly what 'energy' was, I wanted to impress people (women, in particular) by becoming a wise guru in the topic.  However, as the session went on, it became apparent that my grade in the course would not be dependent on such a gratifying endeavor, but rather my ability to succinctly comprehend and manipulate mathematical equations objectively.  The class went very well, and I came to the realization that 'energy' with respect to heat, PV, electrical parameters, quantum mechanics, etc..... is not unique.  Intimacy is not allowed in thermodynamics. 

There is no such thing as the study of q, the study of pV, in and of themselves, the reward of assessing the forms of equations which contain them have specific rewards, which aren't grandiose.  q is a variable at best, and isn't better then H (Enthalpy) or vice versa.  So there's no point in asking what is 'q' rather 'q' can be dH, dU, PV or any combination thereof, there is no 'universal' or 'arbitrary' when it comes to thermodynamics.  Any conceptual basis that are formed before actually being trained in the physical chemistry of thermodynamics must be disregarded in its entirety.

The most common variable in thermodynamics is temperature.  There are so many ways to link an experimental situation to measuring temperature, however, it is often indirect.  In a research grade calorimetry experiment (employing a research grade calorimeter) the temperature change of the water is deemed to be from the caloric content of the "food" source or fuel.  In general chemistry, students are taught to equate the 'q' from the calorimeter with the internal energy.  Yes, enthalpy can be connected soley to an open system setup right?  Not really, or rather, not thermodynamically.  The change in the number of mole equivalence that results from a reaction inside the calorimeter can generate a value in the dnRT component of the change in enthalpy equation.  The change in the nRT state is equivalent to the change in the PV state, and thus the enthalpy is changed. 

Image taken from http://chemlab.truman.edu/CHEM120Labs/Calorimetry.htm

All variables are relevant, unless the value is zero (please correct me on this if I'm being erroneous).

Enthalpy, H, is U+PV

dH, then is equal to H+dH=(U+dU)+(p+dp)(V+dV)=U + dU + pV + pdV + Vdp +dpdV

Enthalpy looks pretty useless right?  Well, a lot of these forms of equations do in physical chemistry.  A really smart individual (perhaps Ed Witten) could comprehend such equations with a good deal of appreciation.  Each of us have our own levels of Eureka moments.  As far as becoming famous is concerned, Ed Whitten would have to condense such equations to a nice simple form that can be useful to someone who doesn't know a lot of math or physics.  The better one can do this, the more useful it is going to be in the industry since the significance of the equation and implications can be applied on a mass scale.  So there's discovery for ya, it's all for the greater good.

dpdV is the product of two infintestimal quantities and is therefore not included.......

H+dH=H+dU+pdV+Vdp

thus dH=dU+pdV+Vdp

We now substitute dU=dq+dw into this equation,

dH=dq+dw+pdV+Vdp

If the situation is where dw=-pdV,

dH=dq+Vdp

if dp is constant (a constant pressure situation), then

dH=q 

The enthalpy is not constant in a calorimeter if the change in the mole equivalence leads to an increase in the relative amount of gases, changing the final PV state from that of the initial one.

Links

http://exploration.grc.nasa.gov/education/rocket/enthalpy.html

During the past few days, I've witnessed people drinking beer or buying beer during the daytime, for instance, I saw a couple of hispanic individuals buying a big can of beer along with their lunch while paying for fuel at a gas station.  Also, it isn't uncommon for people in the construction business to have a can of beer when they're not in the skylines aligning humongous pieces of metal together to form the frame outline of what's going to be a novel building.

People who do this usually can maintain the integrity of their behavior and it seems that a lot of the incentive for drinking at this rather early time of the day is based on a deep rooted philosophy about "who they are" and "what their life is".

In Europe, drinking during the daytime isn't considered extraordinary at all, there aren't any places within the continent that I can recall, or rather that I know of at least.  I for one, don't have this kind of internal philosophy, if I drink a beer during lunch, my IQ would probably drop 40 points.......so I wonder if such a philosophy is important in the road to maturity.  Maybe its a biological thing, alcohol does affect some more then others in relevance to altering their behavior, however, does emotional maturity have anything to do with such differences?  What is your philosophy for drinking? 

This article is meant to be somewhat sarcastic, unless you actually have such a "deep rooted philosophy" of which I would be very interested in finding out about.

 Ladies and Gentlemen, THE MAN.......E.J. Corey 

Today was pretty sobering for me, I spent most of the day alone at a park, taking pictures of migrating geese and people playing with their remote controlled sail boats.  Yep, it seems that the glory days of partying and a fast paced social lifestyle are pretty much over for me.  The pics shall be posted soon.  Yeah, I got a new camera by the way, a Kodak digital camera model C743.  It doesn't actually look the the box and the ad on the web indicates

http://www.kodak.com/eknec/PageQuerier.jhtml?pq-path=9571&pq-locale=en_US&_requestid=4025

it's made out of cheap plastic, and the camera isn't quite as appealing and shiny.  It's endowed with pretty good technology however, and so I'm not gonna return it.

My day at the park, yeah, that arrow is pointing to one of the remote controlled sail boats, there were actually a few more of them, seems that a couple of guys were racing them around the lake coast.

Kyle at http://www.thechemblog.com has posted something interesting at

http://www.thechemblog.com/?p=386

And here's my reply to his post in the comments section associated with this article of his.

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You’ve been quite productive, on a Saturday.

Yeah, some people are just smarter then others and possess a higher form of intellectual facets then others, for science in particular, spatial IQ is quite valuable and some are obviously very good at taking the exact 3D geometric representation of an object rotating it in their minds while others can see merely a vague structure without any concrete details. There’s also the notion of raw brain power, and this probably exists also. Yep, some people are just better endowed and pretty much have it very easy when it comes to success driven by their intellectual prowess and live a totally different existence. 

However, IQ tests are relevant strictly towards diagnosing retardation and the treatment thereof, getting a good score on a IQ test is going to get you into gifted programs; yet a lot of people in gifted programs have been put in to it by delusionally motivated parents. IQ is not a predictive measure of intelligence, it’s simply a criteria for admission into gifted programs. Intelligence can only be really measured by one criteria, and that’s the fruitfulness of one’s career, such as that of E.J. Corey, and Buckminster Fuller; he was in the same gifted program as that of William Sidis, as most of you probably know, the Sidis isolated himself from academia early despite reputed as having the highest IQ quotient ever.

By the way, this is totally going in my blog.

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My last course within the undergraduate chemistry program was independent research, actually, two of them; one was a higher level then the other.  They were taken to satisfy the upper level requirement so that I could graduate earlier and to save tuition money in the process.  The session was during the summer of 2006 and had been extended to fall 2006, which was sort of nice, since I would have probably gotten a pretty bad grade if the report was turned in its condition at that time. 

The professor who advised me throughout the two courses, which was basically taken as one research endeavor, had told me that he would review the report, edit it, and then return it to me so that it could be revised and then graded; this is a very big favor on behalf of him since the average grade for the lab reports during the Analytical Chemistry laboratory course he teaches is ~40%.

It is now Spring of 2007 and my report has yet to be revised.  Is this guy getting paid to extend my sessions?  Or was his initial "favor" more of a sacrifice on his part?  Anyways, I had wrote a rather demanding email to him without considering the latter argument.......if it was the case that he is not getting compensated then my recent contact would probably have been rudely shocking.  I had asked that I take "advantage of the sessions" by having him instruct me further on the instrumentations that are available in his lab, such as the HPLC, GC, particle analyzer, and perhaps the atomic emission spectrometer that is located in a room that is close by.  I also realize that his initial offer of editing my report is a "good" thing in any light, this is something that I had forgotten completely.  A rather rude awakening indeed.......

A lot of us look at the back of a packaged material within the nutritional value content data section to get an impression of just how destructive or healthy a particular product is going to be if it is to be consumed.  However, the data is in percent of daily value, a little more analysis is required to get a notion of exactly 'what' the product actually is.

For instance, a sample cheese package of the Walmart brand, Feather Shredded Colby and Monterey Jack has a number close to 10%-20% associated with the fat as that pertains to the daily value.  The nominal fat in grams per a 28 gram serving is 9 grams, this basically means that the percent in mass that is of fat is 32.14 %.  Water constitutes most of what's in the cheese.  The serving portion, in this case 28 grams of cheese, can be modified to create the effect of a smile on a customer while he or she is loading the product on to the cart as opposed to throwing it on the product counter in disgust.  Yet, most of us probably know just how much of a lard portion we're getting when eating cheese, unless it's low fat cheese.

How accurate is the Babcock fat test, or rather, how skilled am I in producing reliable results through this method? Further statistical analysis may be provided later.  For those of you who aren't familiar with the methodology the following site does a nice job of explaining the history behind it as well as the protocols

http://www.bookrags.com/Babcock_test

The result in percent composition by mass of 9 samples was

Sample #1

30%,31%,31%

Sample #2

32%,31%,32%

Sample #3 

34%,32%,34%

A sample of cheese (sample #1) was taken out of the bag and then placed in a grinder so that the shredded cheese became powdery.  The total mass was divided by 3.1 and three equal amounts of cheese became the representative samples for the Babcock fat test.  Two other samples of cheese in equal mass as that of sample #1 was taken from the product bag and 6 new representative samples were prepared for the Babcock fat test.  All solutions were of reagent grade (email me at gcttutor@yahoo.com) if one desires some of the additional details for this experiment.

The average fat composition of all nine representative samples is then 31.89% which is pretty close to the nominal value.  I'm going to need to do some further statistical analysis on this data, the results shall be posted....perhaps tommorrow.

Figure 1 Pic from nanoscience.com featuring the topographical image of a Langmuir-Blodgett film.  The top arrow points to regions that have been more or less destroyed relative to that associated with the shorter arrow at the bottom.

 Benjamin Franklin analyzing his experiment at the pond within Clapham Common

It was Irvine Langmuir in 1918 who discovered that the constituents of an amphipile monolayer substance can be transferred to a substrate and subsequently placed distinctively on a solid surface (Figure 2); a monolayer that lies above a major liquid influences its surface tension ( 72 mN/m for water, almost zero with a monolayer on top).  Langmuir's assistant, Katherine Blodgett discovered 16 years later that the process could be repeated so as to result in a multi-monolayer stack of any desired thickness essentially making up what is now deemed as the Langmuir-Blodgett film (Figure 1). 

Figure 2 Solid polar substrate is immersed (or emmersed) into the solution to collect the organic monolayer.  More about the details of this phenomena can be found at http://www.ksvltd.com/content/index/keylbfilm .

Applied technology, BAM  http://www.nima.co.uk/basics/basindex.htm

"A monolayer is extremely thin, approximately ½% of the wavelength of visible light. The relative effect it has on the electric field reflected from a water surface is therefore very small and the monolayer is under normal conditions quite invisible. However if the water surface is illuminated with p-polarized light at the Brewster angle, there is no reflection from the water surface. The background is then completely dark and it is possible to make out the tiny effect of the monolayer. This is the principle of the Brewster angle microscope or BAM.  

The BAM was invented independently and almost simultaneously by two groups, that of Jacques Meunier in Paris, France and that of Dietmar Möbius in Göttingen, Germany.  For the first time it was possible to see exactly what a monolayer looked like, and to provide definitive answers to questions which had remained open for 50 years. For example the picture on the left shows the pattern of condensed domains surrounded by a matrix of expanded phase at the main phase transition of a lipid, proving unequivocally that it is a first order transition (Figure 3)."

Figure 3 BAM picture of liquid condensed phase in matrix of liquid expanded phase. DMPE - dimyristoyl phosphatidyl ethanol amine.  

"Modern technological interest in Langmuir-Blodgett (LB) films began with the work of Kuhn, based initially in Marburg, Germany in the late 1960's[5] and later in Göttingen (where his group gave birth to Nima's partner company NFT). Over a decade, Kuhn and his colleagues showed that LB films could be fabricated with all the characteristics required for an information-processing technology in which individual molecules perform distinct functions. They showed not only that the films could be made with molecular-scale patterning, but that previously deposited 'sub-assemblies' could be manipulated to build up more complicated systems[6]. They showed that the built-up films could remain stable for long periods, and that their defect levels were acceptably low[7]. Kuhn's exciting results and his effective communication of them not only around Europe but also around the world inspired many groups to carry on his research. "

From http://www.nima.co.uk/basics/basics1.htm 

More relevance of these monolayers and technological applications (e.g. molecular electronics).......

http://www.nima.co.uk/basics/basics4.htm

I just got an offer for an interview to become a QC Chemist at Barr Pharmaceutical however the position is located at Forest, Virginia.  Don't quite know how nice Virginia is, however, the tasks involved with the position include operating some instruments such as HPLC, GC.......

• Perform instrumental analysis using HPLC, GC, UV/VIS, FTIR, and dissolution with robotics
• Ability to create and maintain lab record documentation (notebooks & computer-based)
• Perform algebraic calculations to quantify test results, computer analysis with chromatographic results for use in a LIMS
• Perform analysis and provide feedback on systems to promote continuous improvement
• Perform routine maintenance of lab equipment as needed

http://www.barrlabs.com

The training on such instrumentations would open a lot of doors in to what type of jobs I can fulfill in the future.  However, I currently live in Georgia and am a bit perplexed regarding why they would seek to hire an employee out of state instead of someone that resides in, let's say, Virginia (Forest, Virginia that is)?

Does this seem to be a good company and is it usually good to relocate for employment, with respect to the establishment of a versatile resume? 

I may get into research in the future, however, money is much more important at the moment.  I absolutely love what you grad students are doing out there, sounds like a lot of fun for some of you detailing such matters in your blogs; fun and frustration at http://www.thechemblog.com

I've recently encoutered a physical chemistry problem which reminded me of just how messy a simple problem can become when it came to sorting out the units.  My P. Chem. professor was Dr. Lionel Carreira, he was highly involved with the development of CARS, however he was pretty easy on us in his tests and quizzes.  The sorting out of the equations wasn't so much of a factor in those exams, a lot of points could have been deducted by simply not keeping track of units.

The root mean square velocity of oxygen molecules is 480m/s while the pressure is 20kPa.

What is the concentration (particles/volume) of oxygen?

Sourced from

http://www.physicsforums.com/showthread.php?p=1216079#post1216079

The equations that were utilized to solve the problem can be found in the page that is hyperlinked to the above text.

The equation to plug in the numbers are pretty simple, however, one has to incorporate the right units for the gas constant, here are just some of them (Figure 1)....... the same goes for the value of k.

You won't find problems like this anywhere in your undergraduate courses besides in Physical Chemistry.  Unless you're of a different major.

(n/v)=20 kPa(1000 Pa/1 kPa)(1.3806503 × 10-23 m2 kg s-2 K-1)3/[8.314472 m^3 · Pa · K-1 · mol-1(16 grams of Oxygen/mole of Oxygen)(1 mole/6.022 x 10^23 atoms)(1 kilogram/1000 grams)(2 atoms of Oxygen/1 diatomic molecule)(480 m/s)^2]= 0.00813782909722 moles/m^3

(0.00813782909722 moles Oxygen/L)(6.022x10^23 molecules Oxygen/mole)= 4.900600682 x 10^24 molecules/m^3

It can get substantially worse....I'm sure you grad students remember.

                                                    Figure 1 Gas constant values obtained

                                                   from Wikipedia 

                                                    http://en.wikipedia.org/wiki/Gas_constant  

I tutored at Kasamba.com and Expertbee.com during my undergraduate years for the purpose of acquiring supplementary income.  On any good month I could earn an extra $400.00, however, this was all after my ratings had gone up to a good extent so that my name appeared on the search results for "Chemistry" on the main page for Kasamba.com.  Tutoring usually consists of providing explanations via email or live chat.  The live chat mode was particularly useful, the client seeking help could actually witness the typing up of the explanation in real time.

The professionals on Kasamba.com are credible, however, none of them are verified (at least not to my knowledge).  The system with Expertbee is a bit different and a lot of their features are currently under development; Wayne, who hosts the site has been helpful all the time.  I've heared reports from my clients, however, that Kasamba.com has been pretty vicious and deceptive when it comes to charging their clients and their customer support department is almost nonexistent (with respect to the professionals who register as tutors their as well as towards client concerns).  Yeah, they are a bit sleazy when it comes to addressing different needs of people who contact them with questions and for help.  I wouldn't be surprised if someone got ripped off and didn't get a response at all.  I've sent a couple of emails to them and at times didn't even get an answer; which impressed upon me that they were utterly disrespectful.  The attitude seems to indicate that they could do business one way or another, they can address the concern of the consumer or not since the majority of them are quite ignorant of how to adequately prosecute secretive institutions.  This type of a demeanor is rather disturbing to say the least and dispicable.

There is only a fax number and an email address for the contact page.  I've not had that many problems with them thus far however and earned a good income; even though they take away 30 percent of the earnings from the session with the client.  However, if anyone has problems with the site, don't go to the Better Business Bureau, better yet contact the Department of Labor and they should be able to assist in the matter or at least provide good references and other directional advice so that the issue at hand can be resolved.

Paul Bracher's in his recent blog article post refers to some of the more unique chemistry websites that have popped up recently as well as the rise of the chemical blogosphere.

http://blog.chembark.com/2006/12/28/news-story-of-2006-the-rise-of-the-chemical-blogosphere/

Such proclaimations for 2007 ("the rise of the chemistry blogosphere") are undue at this point, the establishment of the Chemistry blogging community depends on the existence of blogs that are written by Chemists who have a true appreciation for real Chemistry and that are here to stay. 

So how did the Chemistry blogging community "rise" in the first place?  Yes, the recent trend has been the creation of Chemistry related blogs by students as well as professional chemists, the question is, to what extent would this have been the case if it weren't for blogs such as Tenderbutton.......Dylan Stiles' blog rose to a scale of greatness, not only because it was funny, but mainly because it featured his talent in Organic Chemistry and his genuine appreciation for it.  My first exposure to Chemistry blog was Tenderbutton.com, and in its light, other Chemistry blogs also seemed to have a global purpose.  The prevalence of blogs is quite different from what can be conceptualized as a blogging community; communities are close knit as compared to individualistic population of bloggers who live their existence apart from one another.  I say "global purpose" because the growth of a community depends partly how it manages to connect and draw outsiders.  Well established communities exist to "communicate" and recruit.  The amount of comments in response to a particular blog article is a useful indicator for just how much the individual members of the Chemistry blog community are connecting interpersonally.  Tenderbutton.com drew a lot of comments from professionals in the industry and academia, layman, as well undergraduates. 

A community also exists to relate to other communities.  Dylan's endeavors showed his genuine appreciation for Chemistry; he sacrificed his weekend to engage in "Saturday Night Synthesis", this is what really got him famous with blogging communities that had no other way to relate to Chemistry otherwise (and when he wasn't in the lab, he was busy with other mischievious tasks such as testing out his breathalyzer through an experiment performed on his roomates).  These strange experiments and crazy notions that he had shared with all of us was truly "great" (e.g. using Nair hair remover on ungrateful squirrels, Figure 1).  This type of blog content is what makes the Half Decent Pharmaceutical Chemistry Blog an interesting read also; the guy seems so dedicated ("Albert").  Pipeline is also "great" because it's so opinionated, especially with the actual research topics (e.g. Autism).

Figure 1 Targetting the more freaky squirrels with Nair.  The image was obtained from Tenderbutton.com where Mr. Stiles proposes a method of disgracing a population of squirrels.

Simply put, a nice and healthy "Chemistry blogosphere" needs good Chemistry by Chemists/interns who are established as well as dedicated in their respective field.  Some blogs may express an early interest and fascination with Chemistry, however, they aren't here to stay; Chemistry, like physics and mathematics requires an ability to do Chemistry.  Mitch's site http://www.chemblogs.org demonstrates this notion well, there's a large amount of people registering for blogs, but no increase in material; one particular blog on this site, Chemoblog had generated a lot of comments at one time in the past with actual experimental pictures of what was going on in the lab of the writer-a naive inorganic intern-as well as presentations of matters of practical considerations in troubleshooting some minor problems associated with synthetic approaches (e.g. the best method to keep oxygen out of a compartment)....yet there hasn't been a post in quite a while.  The only consistent blog on Chemblogs.org is  Half Decent Pharmaceutical Chemistry.  Again, it seems that most of the good and lasting blogs are written by individuals who spend a good deal of time pursuing discoveries in their own time or are investigating matters for themselves e.g. doing "Saturday/Friday/Sunday Night Synthesis".  Dylan's most recent article on ChemistryWorld entails his cooking methods, Curry in this case.......he essentially makes the claim that a more "Chemical" approach to cooking yields better results in the quality of the dish. 

It's the appreciation for real Chemistry content that connects the Chemistry blogging community through responsive commentary and criticism and makes it "great".  There needs to be more blogs that appreciates Chemistry like Tenderbutton.com to fill its place (as well as http://www.pipeline.corante.com) so that the Chemistry blogging community can remain established and instead of having a transient existence of blogs written by people who could care more or less about Chemistry.