Why chemistry is so difficult ?

[johncena]

Hey friends, i am posting this message expecting some good suggestions and advices .I have been scoring very good marks in maths , physics and computer science but i am very weak in chemistry.The problem is that i do not like the subject , because unlike maths & all we are not studying the proofs and the derivations of theorems and formulas in chemistry . And it seems to be just studying "by heart". I hate doing problems which i do not understand completely.So can anyone give some suggestions to make chemistry easy for me?

 

[Monique]

There is a lot of logic in chemistry, you just need to know the rules. Maybe you should just spend a little extra time to fully understand the subject.

 

[czelaya]

Any subject that you don't particular like or study earnestly in is going to be difficult. I'm sure if physics and math suite your taste more than you would find physical chemistry to be much more enjoyable. But chemistry is not difficult. I remember when I was an undergraduate and I kept hearing that Organic Chemistry was impossible. I didn't enjoy learning synthesis for but I received all A's in Organic (3 semesters).

 

[pzona]

It sounds like there is more of a problem with your instructor than anything else. Equations and formulas for chemistry can be derived just as easily as they can be for physics or math. If this is your main concern, I would say just try to talk to your teacher after class and see if he can show you how to derive whatever formulas you're working on. My professor did this in class and it helped things go much more smoothly for me. However, if you just don't like the subject, that's fine. Try to get through it, and then after you've done as much as you need to do, move on to something else. Chemistry isn't for everyone, just like physics or math. Do what you like, and what you're good at, and things will be much easier for you.

 

[symbolipoint]

Things become messy as you move from Math & Physics toward other sciences; maybe you'll find Biology worse (more difficult and messy, seemingly less systematic) than Chemistry. You have many different properties and qualities to learn about in Chemistry which are somewhat less or differently emphasised in Physics.

One way to learn more comfortably is to start in simpler, less advanced courses and then study the courses in sequence; not skipping any of them. If you have gone from high school college prep. math straight into General Chemistry in college, then this can be very tough to handle. Think of these:

Intro Chem - light, interesting, not very rigorous.
Elementary Chem - Some need for math, maybe just Algebra 1 needed; looks at qualitative information mostly.
General Chem - NEED Algebra 2. Rigorous, much deeper than Intro or Elem. Intensive, relating to some physics knowledge, even though Physics sequence were not prerequisites.

 

[johncena]

It sounds like there is more of a problem with your instructor than anything else. Equations and formulas for chemistry can be derived just as easily as they can be for physics or math. If this is your main concern, I would say just try to talk to your teacher after class and see if he can show you how to derive whatever formulas you're working on.

I asked the teacher but she said that the derivations was too tough and lengthy and there isn't any use of wasting time for things which is not in the syllabus.
But sir, I hate studying theorems without knowing the proof of it , So, can i use this forum to know the derivations that i needed ?

 

[Monique]

Yes, you can post your question in the appropriate sub-forum. Doesn't your book give the derivations? Every book I studied from showed how the formula was constructed. You shouldn't waste too much time doing this from scratch.

 

[symbolipoint]

More thought about this:

Suggestion for making Chemistry BETTER for you but not EASIER for you --
Your book should show algebraic derivations for some quantities. If you find none, then refer to another book. Introductory textbooks might have no derivations but General Chemistry books will have many of them.

 

[vaibhav1803]

I hate doing problems which i do not understand completely.So can anyone give some suggestions to make chemistry easy for me?

since u hate the work, u can't feel it is easy...so u'd rather buck up by startin from a lower level and then rise slowly..
ciao.

 

[pzona]

Here's a link to my general chem course's website. I'm not sure what subjects you're covering, but the supplemental reading material on gas laws, Lewis structures, etc. were very helpful to me. They have a lot of good information on where some equations come from (the Clausius-Clapeyron derivation is particularly detailed), and at the bottom of the page are some really good links. Hopefully at least some of this can be of some use.

http://courses.chem.psu.edu/chem110h/

 

[emyt]

I have this same problem, I'm a math student but I want to switch over to material science.. studying chemistry right now feels like I'm going through a history book - I don't know the physics behind their claims so I can't see how the equations are derived.. I'm reading a book called "General Chemistry" by Linus Pauling, should I find something else to read? I feel like chemistry would be really cool once I get past this barrier, but so far it makes me nervous

thanks a lot

 

[turbo]

Maybe there is a problem with the structure of the course? In my university (stone-age days) we were immersed in lectures, recitations, and labs that progressed from qualitative analysis to quantitative analysis (inorganic) and then on to organic chemistry. The courses were well-structured, rigorous, and well-buttressed by theoretical teachings. I'm not saying the courses were easy...the predicted attrition rate was 300+ freshmen in, fewer than 100 graduates out with Chem E BS degrees.

 

[emyt]

Maybe there is a problem with the structure of the course? In my university (stone-age days) we were immersed in lectures, recitations, and labs that progressed from qualitative analysis to quantitative analysis (inorganic) and then on to organic chemistry. The courses were well-structured, rigorous, and well-buttressed by theoretical teachings. I'm not saying the courses were easy...the predicted attrition rate was 300+ freshmen in, fewer than 100 graduates out with Chem E BS degrees.

can you really study chemistry "rigourously" without the knowledge of more advanced concepts in physics? that's one of my concerns.. thanks

 

[turbo]

can you really study chemistry "rigourously" without the knowledge of more advanced concepts in physics? that's one of my concerns.. thanks

In my Uni, chemistry was very practical and results-oriented. The pulp and paper industry sponsored high-performing students and paid a lot of their way if they would track into a curriculum that concentrated on producing engineers for the industry. I didn't see a disconnect between physics and chemistry in the curriculum. BTW, this was all 40 years ago, so your mileage may vary.

I remember when the Student Aid director called me to his office and told me that I was one of 5 students in my class to get a 5-year scholarship through the Pulp and Paper industry's sponsorship. I told him that I didn't want it because I had decided to switch to liberal arts, and he said "I'm going to call your parents." I said "I already told them". I still ended up as a Process Chemist in a brand-new pulp mill a decade later. Fate is a fickle thing.

You're not old enough to have ever seen Rowan and Martin's "Laugh-In", but they had a recurring segment giving the "Fickle Finger of Fate" award for public events. It was a good spot.

 

[emyt]

In my Uni, chemistry was very practical and results-oriented. The pulp and paper industry sponsored high-performing students and paid a lot of their way if they would track into a curriculum that concentrated on producing engineers for the industry. I didn't see a disconnect between physics and chemistry in the curriculum. BTW, this was all 40 years ago, so your mileage may vary.

I remember when the Student Aid director called me to his office and told me that I was one of 5 students in my class to get a 5-year scholarship through the Pulp and Paper industry's sponsorship. I told him that I didn't want it because I had decided to switch to liberal arts, and he said "I'm going to call your parents." I said "I already told them". I still ended up as a Process Chemist in a brand-new pulp mill a decade later. Fate is a fickle thing.

You're not old enough to have ever seen Rowan and Martin's "Laugh-In", but they had a recurring segment giving the "Fickle Finger of Fate" award for public events. It was a good spot.

thanks a lot for the replies.. what do you think would be my best course of action? bear with the physics until I actually learn them in physics? (thermodynamics, temperature, light, Planck's constant... et c are things I haven't really studied yet) or is there a book better suited for my situation? I just really don't like taking things for granted

 

[turbo]

thanks a lot for the replies.. what do you think would be my best course of action? bear with the physics until I actually learn them in physics? (thermodynamics, temperature, light, Planck's constant... et c are things I haven't really studied yet) or is there a book better suited for my situation? I just really don't like taking things for granted

When I was in college, I looked at physics as an abstract field, grounded in experimentation and math, and chemistry as a more hands-on practical field grounded in real-world experimentation. I don't know why, but that might have been motivated by my desire to stay in Maine and work as a professional in a high-paying job.

Please don't base your decisions on my experiences in college and work. I've made a lot of mistakes, and sometimes things turned out really well in spite of (or because of) them.

 

[emyt]

When I was in college, I looked at physics as an abstract field, grounded in experimentation and math, and chemistry as a more hands-on practical field grounded in real-world experimentation. I don't know why, but that might have been motivated by my desire to stay in Maine and work as a professional in a high-paying job.

Please don't base your decisions on my experiences in college and work. I've made a lot of mistakes, and sometimes things turned out really well in spite of (or because of) them.

I guess it's a matter of changing my attitude then, it seems like I have to change my philosophy of science to cope with studying chemistry haha

thanks for replying

edit: do you know if Linus Pauling's "General Chemistry" is a good book for someone who is starting out in chemistry?

 

[symbolipoint]

emyt,
Since you are trying to decide about changing major fields and you think you are interested in Chemistry because of it being close to materials science, you possibly are interested in both Physics and Physical Chemistry.
Yah, you can study Chemistry with the bare minimum of Physics knowledge presented in the Chemistry course, but as you progress to other courses you NEED more Physics knowledge - which come from other required courses for a Chem. degree program. Those 'bare minimum' Physics courses are not always enough. MORE Math & Physics can be very useful, NOT LESS Math & Physics. Several ideas from Physics are important in getting a good understanding of Physical Chemistry and in getting good understanding of how quantitative analyses are managed (instruments, radiation, equipment).

 

[emyt]

emyt,
Since you are trying to decide about changing major fields and you think you are interested in Chemistry because of it being close to materials science, you possibly are interested in both Physics and Physical Chemistry.
Yah, you can study Chemistry with the bare minimum of Physics knowledge presented in the Chemistry course, but as you progress to other courses you NEED more Physics knowledge - which come from other required courses for a Chem. degree program. Those 'bare minimum' Physics courses are not always enough. MORE Math & Physics can be very useful, NOT LESS Math & Physics. Several ideas from Physics are important in getting a good understanding of Physical Chemistry and in getting good understanding of how quantitative analyses are managed (instruments, radiation, equipment).

you're right about me "thinking" that I would like chemistry, I really think I would. I'm not uninterested, it's just that some of the information seems like it would normally be out of my depth (quantum mechanics?). I'm not objecting against studying more physics, it's just that I'm still learning lower level mechanics and the first page of my chemistry book talks about E = mc^2. I don't think MOST people are up to date on quantum mechanics upon entering their first year in chemistry..

an example of what I mean is like in my book, the laws are presented as "this guy experimented and discovered that x is like y", whereas in physics and math it would be more centered on WHY this is true


I really think chemistry would be something I would like, and the material science program requires you to take a lot of chemistry as well.

thanks a lot for replying I appreciate it

 

[Borek]

I'm still learning lower level mechanics and the first page of my chemistry book talks about E = mc^2.

But it doesn't want you to know anything more at this stage - accept that E=mc² and you will see where and how it may play a role. Why E=mc² doesn't matter at this stage.

I don't think MOST people are up to date on quantum mechanics upon entering their first year in chemistry..

That's why no chemistry course starts with Schroedinger's equation

an example of what I mean is like in my book, the laws are presented as "this guy experimented and discovered that x is like y", whereas in physics and math it would be more centered on WHY this is true

Chemistry is much more experimental science. It is not that chemists are not interested in WHY, but the real world is pretty complicated. In effect sometimes when we filter out everything that interferes with our understanding of WHY, we are left with a simple rule that is completely useless, because it doesn't describe the real systems. So before you can look at these detailed rules you have to get a feel of how the reals systems behave, to understand limitations.

--
methods

 

[emyt]

But it doesn't want you to know anything more at this stage - accept that E=mc² and you will see where and how it may play a role. Why E=mc² doesn't matter at this stage.
That's why no chemistry course starts with Schroedinger's equation
Chemistry is much more experimental science. It is not that chemists are not interested in WHY, but the real world is pretty complicated. In effect sometimes when we filter out everything that interferes with our understanding of WHY, we are left with a simple rule that is completely useless, because it doesn't describe the real systems. So before you can look at these detailed rules you have to get a feel of how the reals systems behave, to understand limitations.

--
chemical calculators - buffer calculator, concentration calculator
www.titrations.info - all about titration methods

Thanks a lot for this message, these are really good points. I suppose that the main goal of chemistry IS to explain the REAL world - not some mathematical axiomatic system that may only be relevant to itself. So, clearly experimentation would probably have more of a priority than "theory". Also, it was a good point you brought up about how we should start by studying through observations of "real" systems before becoming theoretical - after all, this is probably how all sciences were born.

Thanks for your input, I'm much more comfortable now with my ignorance of quantum mechanics and other physical laws I may have to take for granted. Well, comfortable in knowing that I should at least learn about those theories and laws later in my educational career.

this might be a stupid question but, do chemists/ chemistry majors usually end up (somewhere down the line) actually understanding (by understand, I mean comprehensively, on a "physics" level) all of those physical laws including quantum mechanics? It seems like you'd need a lot of math for that, and the chemistry programs I've seen seem to be more lenient in how the student takes his math courses.

 

[Borek]

this might be a stupid question but, do chemists/ chemistry majors usually end up (somewhere down the line) actually understanding (by understand, I mean comprehensively, on a "physics" level) all of those physical laws including quantum mechanics? It seems like you'd need a lot of math for that, and the chemistry programs I've seen seem to be more lenient in how the student takes his math courses.

Many chemists - including highly succesfull professors - don't know much more about quantum chemistry than what is covered in general chemistry, or at best in some Quantum 101. Trick is, for many applications this knowledge is completely irrelevant. That is - you have to know what orbitals are, how they are filled, how they can create molecular orbitals, bonding, antibonding, what are their shapes - but it many cases it is enough to have good intuition about these things, intuition that is not followed by strict understanding of the math behind the description.

And in fact knowing how these things can be calculated is not necesarilly helpfull (in practical terms), as most real systems are still too complicated to be analyzed (calculated) using quantum chemistry methods. They are getting better, but we are not yet in the place where computer wins over the test glass

--
methods

 

[emyt]

Many chemists - including highly succesfull professors - don't know much more about quantum chemistry than what is covered in general chemistry, or at best in some Quantum 101. Trick is, for many applications this knowledge is completely irrelevant. That is - you have to know what orbitals are, how they are filled, how they can create molecular orbitals, bonding, antibonding, what are their shapes - but it many cases it is enough to have good intuition about these things, intuition that is not followed by strict understanding of the math behind the description.

And in fact knowing how these things can be calculated is not necesarilly helpfull (in practical terms), as most real systems are still too complicated to be analyzed (calculated) using quantum chemistry methods. They are getting better, but we are not yet in the place where computer wins over the test glass

--
chemical calculators - buffer calculator, concentration calculator
www.titrations.info - all about titration methods

Ah I see, thanks. But it's probably true that if you are to make any big discoveries or come up with any enlightening theories, you should probably know what's going on with the physics behind the chemistry right?

 

[Borek]

The more you know the better, it makes understanding of all aspects of what is going on easier. That's for sure.

--
methods

 

[hiuting]

There's a lot of memorization involved. BUT, there's a lot of logic to it too. So spend time really understanding, and you'll do fine. :) i just failed a chem quiz, but that's 'cause i didn't study and didn't try understanding. i don't like memorizing stuff either... and i need to spend a lot of time understanding EVERYTHING. .. so you're not alone here. hang in there!

 

[PhaseShifter]

this might be a stupid question but, do chemists/ chemistry majors usually end up (somewhere down the line) actually understanding (by understand, I mean comprehensively, on a "physics" level) all of those physical laws including quantum mechanics? It seems like you'd need a lot of math for that, and the chemistry programs I've seen seem to be more lenient in how the student takes his math courses.

It depends on the branch of chemistry you specialize in.

Physical chemistry-the theoretical stuff is your bread and butter.
Analytical chemistry-You'll need to know a fair bit to decide which techniques are preferable for a certain analysis. (i.e. is a compound easier to detect and measure with infrared, raman, or UV-visible spectroscopy?)
Organic/inorganic synthesis-not so much, unless you're trying to produce a substance with unusual physical properties.

 

[PhaseShifter]

There's a lot of memorization involved. BUT, there's a lot of logic to it too. So spend time really understanding, and you'll do fine. :) i just failed a chem quiz, but that's 'cause i didn't study and didn't try understanding. i don't like memorizing stuff either... and i need to spend a lot of time understanding EVERYTHING. .. so you're not alone here. hang in there!

The problem with not starting out with the more advanced theories is the simpler ones tend to have lots of exceptions. For instance, the octet rule works really well for elements between boron and aluminum on the periodic table, but it NEVER applies to hydrogen or helium, and doesn't work so well for heavier nonmetals when oxygen is also involved. By the time you learn molecular orbital theory the reasons for the exceptions become obvious, but the rule seems like a good idea because we're used to dealing with that limited group of elements most of the time.

Also, I've noticed that general chemistry courses tend to separate certain subjects that should really be combined--for instance, electrochemistry and thermodynamics. If you take the Gibbs free energy of reaction for a redox reaction, and convert it from the standard units of kJ/mole to Joules/coulomb of electrons transferred, you get the Nernst equation. I don't know why it's taught as two completely separate subjects when it's basically a simple matter of converting units to get from one to the other.

 

[emyt]

It depends on the branch of chemistry you specialize in.

Physical chemistry-the theoretical stuff is your bread and butter.
Analytical chemistry-You'll need to know a fair bit to decide which techniques are preferable for a certain analysis. (i.e. is a compound easier to detect and measure with infrared, raman, or UV-visible spectroscopy?)
Organic/inorganic synthesis-not so much, unless you're trying to produce a substance with unusual physical properties.

cool , physical chemistry looks interesting

thanks

 

[windwitch]

It sounds like there is more of a problem with your instructor than anything else. Equations and formulas for chemistry can be derived just as easily as they can be for physics or math. If this is your main concern, I would say just try to talk to your teacher after class and see if he can show you how to derive whatever formulas you're working on. My professor did this in class and it helped things go much more smoothly for me. However, if you just don't like the subject, that's fine. Try to get through it, and then after you've done as much as you need to do, move on to something else. Chemistry isn't for everyone, just like physics or math. Do what you like, and what you're good at, and things will be much easier for you.

I completely agree with this poster. I believe that to learn science or math properly, you should be able to understand what you are doing. There should never be a moment when you are blindly using an equation, just because your givens just happen to fit into the equation. It is absurd.

Assuming your instructor is not flexible (as you have already said) in the teaching of these proofs, maybe you would want to do some independent studying. It already seems as though you are motivated enough to attempt to learn chemistry so I can't see the harm is asking you to learn the proofs of every equation you learn.

EDIT: Also, most of the concepts in chemistry borrow from physics and since you seem to be more interested in physics, perhaps you can also research physical proofs of chemical concepts.

 

[Hunterbender]

I don't have a solution, but I just want to tell you that you aren't alone. I love physics, I enjoy biology...but I can't stand chemistry. For me, a big part of it was my HS experience. But now I am trying to understand Chemistry from a physical perspective, but it's definitely harder [at least for me] than physics.

 

[sponsoredwalk]

More thought about this:

Suggestion for making Chemistry BETTER for you but not EASIER for you --
Your book should show algebraic derivations for some quantities. If you find none, then refer to another book. Introductory textbooks might have no derivations but General Chemistry books will have many of them.

I whole heartedly agree with this statement.

Only today did I realize how to derive the easy formula for switching between Fahrenheit and celsius. I know it's a tiny thing but EVERY chemistry page I've read that attempts to teach this concept just forces you to memorize it, but if they explained that it's easily derivable from the slope formula in mathematics I would remember it forever (as I will!).

Currently I'm awaiting my copy of Linus Pauling's General Chemistry for my last attempt at chemistry. I would recommend the OP to check this book out as this is the guy who stubbornly claimed chemistry was all about first principles and was so close to deriving DNA off of first principles (but those beautiful hydrogen bonds got in his way ).

 

[Dakaa]

Hey friends, i am posting this message expecting some good suggestions and advices .I have been scoring very good marks in maths , physics and computer science but i am very weak in chemistry.The problem is that i do not like the subject , because unlike maths & all we are not studying the proofs and the derivations of theorems and formulas in chemistry . And it seems to be just studying "by heart". I hate doing problems which i do not understand completely.So can anyone give some suggestions to make chemistry easy for me?

lol same, i hate biology and chemistry, you learn everything by heart, which is stupid, they don't show proofs and theories at school, so are geo and history.

 

[snshusat161]

In physical chemistry each and every formula's have derivation, so it is not hard to study. Organic Chemistry is really challenging for me. It is challenging because the same concept work for one compound but doesn't work for other.

In organic chemistry I feel that whenever they are going wrong they propose a new concept to prove the actual. To understand what I mean to say let's take an example. If you don't know any answer in Maths and Physics, You try to calculate it using concepts and formula's. But if I'll tell you that the answer calculated by you isn't right (even when you've used the right concept and formula) then You'll say may it is due to that... That the same thing happening on organic chemistry.

 

[Borek]

Only today did I realize how to derive the easy formula for switching between Fahrenheit and celsius. I know it's a tiny thing but EVERY chemistry page I've read that attempts to teach this concept just forces you to memorize it, but if they explained that it's easily derivable from the slope formula in mathematics I would remember it forever (as I will!).

Trick is, most of the students learning chemistry already failed at math much earlier, and solving y=ax+b for x is beyond their reach. Even solving y=kx for x is too difficult for many. Tell them they need math and they have just failed chemistry, as they know it is not for them.

This is a situation without a good solution.

 

[Jon Richfield]

Hey friends, i am posting this message expecting some good suggestions and advices .I have been scoring very good marks in maths , physics and computer science but i am very weak in chemistry.The problem is that i do not like the subject , because unlike maths & all we are not studying the proofs and the derivations of theorems and formulas in chemistry . And it seems to be just studying "by heart". I hate doing problems which i do not understand completely.So can anyone give some suggestions to make chemistry easy for me?

You don't say what course you are doing; it could be anything from grade10 to postgraduate. I am not a chemist, but a biologist (sortakinda). I did have enough abstract aptitude to enjoy maths, physics, computer science, etc (Long story, never mind the details.) However, I never could understand school chemistry until in grade 11 our teacher explained orbitals, and everything fell into place for me and a lot of the brighter guys in class (Nothing against ladies, me, it just happened to be a boys school! Worse luck!) Suddenly chemistry had a logic! Strangely, the less errr... intellectual guys (not altogether denigratory btw; some of them really were intelligent) suddenly stopped "understanding" chemistry. I didn't understand that, but that was the way it worked.

Now, in phys and maths the (call it) "axiomatic" part of the work, the part that the rest of the work was based on tended to be small. You learned a few "facts", "givens" if you like, and based the rest on that, with great rigidity. In chemistry there are more givens and often less precise derivations. However, if you can clarify the basic ideas in your textbooks plus memorise such things as the part of the periodic table that you are working on, then you should be able to manage very well and chem becomes almost automatic. In may case what happened to me was that I had a great interest in explosives. So, since that was not what they were teaching in class, I had to do a lot of reading. This did wonders for my chemical insights, and first thing you knew, I was enjoying chemistry, even after my interest in explosives waned.

As for biology, a lot of it involves brute-force learning; the axiomatic part is indefinitely large. But here there is room for a lot of types of intellect. Some just happen to like learning huge amounts of material. Some, like me, prefer logical aspects such as ecological interactions, selective adaptation, biochemistry, ethology, and so on. It has nothing to do with one field of study being "better" than another, just a different mental approach. Biochemistry was a boring bastard till I got into the metabolic pathways; then it was beautiful. But a lot of budding biologists found it all fear and loathing forever. Even though they could not fully understand their own fields without it.

OK. Bottom line. Make sure you understand the basics. If the teacher cannot or will not help, do your own reading. Combine your textbooks with what they have in the libraries and what you can find in google, wiki etc. Then you probably will find that windows begin to open and reveal a really nice outlook.

I am new in this forum, but the folk generally look nice. Keep asking, but try really hard to answer each question for yourself before you do; you will find that some of them clear up by themselves, and each such victory leaves you with what you had seen as meaningless rote material suddenly making sense.

Good luck,

Jon

 

[Jon Richfield]

lol same, i hate biology and chemistry, you learn everything by heart, which is stupid, they don't show proofs and theories at school, so are geo and history.

You have no idea how saddening this is. I don't know what to do about it, but if you can escape the poison in the syllabus, and learn things with comprehension and make a point about seeing how they hang together, you can make sense out of geography, biology, geology, astronomy, and even in some cases and in some senses, even history and propaganda. It basically becomes a matter of alert observation and making connections without forcing connections.

Sometimes the process is subtle.

Try this one for an example. I was being dragged around a golf course in Western Australia. Oz is a fascinating continent but half totally alien to me and half misleadingly similar to my home ground. And a tree some 50m away from the fairway suddenly seemed to have the wrong texture in a particular tuft of foliage. I became intrigued, wandered off, and when I was just a metre or so from the branch, I realized that the foliage was sheltering a pair of tawny frogmouths. They were not part of the growing scheme of the tree, you see? You might say there was a logical discontinuity, right? I still don't know the species of Banksia, but my eye could tell that there was an inhomogeneity. Am I getting through?

I could not have done that before I had developed field experience that told me that there was more to a tree than brown trunk and green leaves.

But the birds were so well camouflaged that our photos failed. In real life we could see that the frogmouths were adapted to look like broken branches and in this respect their logic was so precise that of the hundreds of golfers that passed them daily, hardly one in a hundred ever spotted them, and then by accident.

Every non-trivial subject has its own logic. Not everyone has the aptitude to see it. But a bit of good hard work at the start might make the rest of the course a breeze, an enjoyable breeze, and enrich your world tremendously.

Trust one who has tried a few of the fields

Jon

 

[johncena]

I am having the same problem with matrices and determinants...it is really fun doing problems ,but i wan't to know where did this rules come from (rules for matrix operations & determinants)

 

[sponsoredwalk]

I am having the same problem with matrices and determinants...it is really fun doing problems ,but i wan't to know where did this rules come from (rules for matrix operations & determinants)

Have you ever heard of Linear Algebra?

If you're only learning about this stuff in high school then It doesn't surprise me that it's confusing you, it'll all make sense once you take linear algebra.

http://ocw.mit.edu/OcwWeb/Mathematics/18-06Spring-2005/VideoLectures/index.htm

http://tutorial.math.lamar.edu/Classes/LinAlg/LinAlg.aspx


Anyway, back to Chemistry, I got Linus Pauling's book the other day and have started it, it seems pretty good so far!

 

[walkerr]

Chemistry is about half way between Physics and Biology. In Physics, students learn to derive and utilize formulas. In Biology, there are no formulas, only memorization of facts. In chemistry, there are many "tools" which must be memorized before one can solve problems in chemistry. These include electron configurations, ionic charges, electronegativity values, nomenclature rules, element symbols, certain formulas, such as the ideal gas law, and many others.

The fact that these "tools" are presented without derivation in the General Chemistry course may present a stumblingblock to math and physics majors, who are not used to taking things on "faith". However, all of these concepts are rigorously proven in the Physical Chemistry course.

 

[chill_factor]

Things are not proven in lower division chemistry because new students are simply not good enough at math and physics to handle the proofs which are seriously hard to prove. Even something as "simple" as chemical bonding in H2+ (the simplest "molecule" possible, with just 2 protons and 1 electron) requires at the minimum a strong understanding of quantum mechanics, at least wave mechanics, with all the corresponding math. Multielectron atoms also cannot be derived with anything less than full on quantum mechanics.

If you tossed Ira Levine's "Quantum Chemistry" at a first year they're going to give up and major in psychology or business instead. Why do you think 1st year physics classes aren't going over conformal mapping to calculate capacitance of non-concentric wires and the like?

The reason the derivations are saved for 3rd year physical chemistry and 4th year quantum/computational chemistry (elective) is because they're simply too hard without already taking Calculus 1-3, Linear Algebra and ODEs.

Want rigorous derivation? You think you can handle it? "Molecular Quantum Mechanics" by Atkins and Ira Levine's "Quantum Chemistry" are good places to get started.

 

[JohnRC]

One of the reasons that chemistry is so difficult for almost everyone is that it involves so many very different conceptualization schemes. I note, for example, that the OP said that s/he has no difficulty with the formulas and with phys chem generally. All of us educators are used to students of chemistry having difficulty with the mathematical side, and I think that most of the replies have missed this particular point in the original post and proceeded to discuss the reasons why students have difficulty with the mathematical side of chemistry.

There are equally difficult problems in learning the inorganic/organic sides of chemistry as well -- more difficult for some, and not so often recognised by others.

(1) Generalizations and systems: The biggest difficulty that students have with the descriptive side of chemistry is recognizing the appropriate generalizations. They treat chemical properties as a number of individual facts to be memorised and regurgitated at examination time. After a while the sheer volume of facts becomes unmanageable. It is vital that a student make the breakthrough to recognise the patterns that properties follow, and to recognise the subtle variations that go with changing the structure. How properties of inorganic materials differ if you substitute an atom with another from the same periodic table group, for example, or how the behaviour of a particular organic functional group will change in a compound if you attach it to a heavier framework, or a sterically crowding framework, or an electron withdrawing framework.

The other side of this is that textbooks and teachers tend to over-emphasize similarities by "force-fitting" borderline cases, so that the real compounds that students actually meet in the lab do not quite match the expectations when a "rule of thumb" is interpreted as a strict law of nature.

(2) Symbolic representations: In most other branches of science, artificial representations are far less central than they are in chemistry. The bonding calculus pervades everything: single bonds, double bonds, polar bonds, ionic bonds, co-ordinate bonds. Students get terribly confused, and textbooks can get terribly dogmatic. The second chemical formula that most students learn to use is sulfuric acid: H2SO4. But there are three quite different ways of writing a structural formula for sulfuric acid, each of them valid in some ways, and problematic in others. It does not help when a particular textbook suggests that one of them is right and others are wrong. But it also can lead to confusion of you try to introduce students to the reality of the situation: nature does not know about formal charges or double bonds or co-ordinate bonds -- they are accounting devices introduced by chemists to approximately represent the situation. And there is the fact that the four oxygen atoms in sulfate ion are exactly equivalent does not fit with any structural representation until and unless we introduce the concept of six equivalent resonance structures, no less!

(3) While we are on the example of sulfuric acid, it is important to point out a third area where students of chemistry have difficulty -- understanding three-dimensional objects. The whole of the education system focuses on two dimensional media -- books, projector screens, computer screens. It is important to obtain a thorough understanding of 3-dimensional objects by actually handling them, not just visualizing them. Many of my students could not deeply understand why there were not cis- and trans-versions of the sulfuric acid molecule -- they just had to take it on trust! Nearly all students have difficulty understanding chirality, and even more difficulty in working with it in structures with more than one chiral centre. Or even recognizing when it would arise. (Most, for example, fail to recognize that 2-butanol is chiral unless it is pointed out to them.

A lot of the ways that chemists have to think are completely different to those employed in other areas of science, or indeed in non-science subjects either. It is small wonder that chemistry is found to be difficult.

 

[member 392791]

I've found the lab component of chemistry to be significantly harder than physics, while the physics theory is more difficult to understand. However I'm only comparing lower division chemistry and physics and extrapolating it to the entire field, I could certainly be wrong but most of my chemistry professors seem to be math-incompetent relative to the physicists.

 

[JohnRC]

I've found the lab component of chemistry to be significantly harder than physics, while the physics theory is more difficult to understand. However I'm only comparing lower division chemistry and physics and extrapolating it to the entire field, I could certainly be wrong but most of my chemistry professors seem to be math-incompetent relative to the physicists.

Only in Physical Chemistry is any sophisticated maths used as such. Analytical chemistry involves a lot of arithmetic, but sophisticated maths comes in only at the research level with differential calculus and statistics.

Many organic and inorganic chemists hardly need to use maths at all, and yet the sorts of manipulations they use to work out structural possibilities, reaction mechanisms, routes for synthesis really involve quite sophisticated informal mathematics in manipulations of bonds, formal electron transfers for reaction pathways ("curly arrows"), rough considerations of polarization effects, and the like.

They are deeply involved with manipulations of formal symbols that they use to represent substances, and with translations of these symbols at two levels :
• "accounting electrons" to "actual electrons", and
• "actual molecular scale machinations" to bulk material behaviour.

These fundamental parts of the modern chemical body of understanding are quite "mathematical" in their character, and yet are seldom if ever dealt with in the way that formal mathematics would approach them, and never incorporated into a formal mathematics syllabus.

 

[member 392791]

Right now I'm taking organic chemistry and it is by no means trivial..in fact I'm doing the worst in that class between linear algebra/diff equation and physics. I could be a more systematic thinker, but o-chem has something special about it that is making it very frustrating for me. The concepts don't seem that deep, but perhaps the way the questions are proposed is harder for me personally.

I mean there's no way isomerism is more complicated than vector spaces, but if you ask me to draw all isomers of C8H18 on the exam..I might not be able to do it.

 

[JohnRC]

Right now I'm taking organic chemistry and it is by no means trivial..in fact I'm doing the worst in that class between linear algebra/diff equation and physics. I could be a more systematic thinker, but o-chem has something special about it that is making it very frustrating for me. The concepts don't seem that deep, but perhaps the way the questions are proposed is harder for me personally.

I mean there's no way isomerism is more complicated than vector spaces, but if you ask me to draw all isomers of C8H18 on the exam..I might not be able to do it.

You are quite right, and this is exactly what I am talking about. A problem like this is not beyond the scope of a formal mathematical representation. But setting one up and getting it right is not a practical way to go about it in a test situation.

Chemists tend to approach this type of problem in a more instinctive, rule-of-thumb sort of way that would be frowned on by most mathematicians. And they do not always get the right answer.

For this particular problem a chemist would probably develop an algorithm that would be an attempt to make a systematic direct count --

----- chemist type algorithm ----
first there is octane.
Now what about heptanes -- how many different places can you put a methyl substituent? Three -- the 2, 3, & 4 positions. (A really clever chemist would here recognize that 3-methylheptane is chiral, giving rise to two different isomers. Most would not)
Next try hexanes. They can be either dimethylhexanes or ethylhexanes. How many of each? (and which of them, if any, are chiral?)
Then we can consider pentanes, which must be either trimethyl or ethylmethyl.
And that leaves a single tetramethylbutane, the only possibility, because any substituent longer than a methyl on a butane would make a pentane.
------

I venture to suggest that that is the way that most chemists would go about this problem, and that it is quite different to the approach that a mathematician or a physicist would use.

 

[DrDu]

At least in Germany, I see a serious problem with the formation of high-school teachers. They are trained to teach not only one subject, but two. However, these combinations can not be chosen freely. Most chemistry teachers have the combination chemistry/biology and most physics teachers physics/mathematics. So while the physics curriculum takes into account the mathematical background available at any given level, chemistry curriculum avoids mathematical arguments where possible.

 

[JohnRC]

At least in Germany, I see a serious problem with the formation of high-school teachers. They are trained to teach not only one subject, but two. However, these combinations can not be chosen freely. Most chemistry teachers have the combination chemistry/biology and most physics teachers physics/mathematics. So while the physics curriculum takes into account the mathematical background available at any given level, chemistry curriculum avoids mathematical arguments where possible.

That is also the case here in Australia DrDu. We also require high school teachers to be 2-subject trained, and we have a far less rigid structure than Germany. But most of our senior chemistry teachers are essentially biologists, because biology courses are a lot more popular than chemistry courses at university level, and biology graduates are a lot less employable.

In my particular state this is exacerbated by the general rule that a teacher cannot take a class at the top high school level in a subject unless they have at least a second year university level pass in that subject. But in the case of chemistry, biochem 2 is recognised as fulfilling that condition; it does not have to be chemistry 2.

So chemistry tends to be taught at high school level as a purely descriptive subject, centred on memorizing a lot of facts, and the systematic infrastructure and modes of thinking that are distinctive parts of chemistry are not understood nor expected by students. And that difficulty stands quite separate from a generally lower level of engagement with higher maths on the part of both teachers and students of chemistry.

When students hit university level chemistry, they still expect it to be a fully descriptive subject, and often they are quite resistant to developing a conceptual framework, so that they get overwhelmed by a huge number of facts that they cannot relate to one another. They have genuine difficulties with the whole of chemistry, not just the small part that might relate to an inadequate maths background.

 

[Borek]

This thinking - that chemistry is mostly descriptive - is popular throughout the world, not limited to Germany and Australia. Plenty of students are surprised that they need to use simple algebra to solve the chemistry problems ("what do you mean two equations with two unknowns, this is chemistry"). I have seen it personally in Poland, but judging from the forums it happens everywhere.

 

[DrDu]

Exactly, I remember that we spent a considerable time (at least one term) in high school on how to balance equations, using some vodoo formalism and then another term learning how to balance redox equations using this obscure oxidation number formalism.
It came as a revelation when I found out that both reduce to simple problems of linear algebra from the equations of conservation of atom numbers and charge.
Another term wasted on learning thousand special cases on how to calculate pH along a titration curve. Again instead of starting from the complete set of equations and then introducing approximations, only thousands of special cases were treated without showing first the general picture.

 

[Borek]

Another term wasted on learning thousand special cases on how to calculate pH along a titration curve. Again instead of starting from the complete set of equations and then introducing approximations, only thousands of special cases were treated without showing first the general picture.

You may like top-down approach presented here then: http://www.chembuddy.com/?left=pH-calculation&right=toc