Heuristics
How to Survive Basic Chemistry
In many high schools and colleges the basic chemistry course is the one that causes most concern among students. With everything going right, chemistry can be a fun but challenging course. Under poor conditions, your first chemistry course can be a real nightmare. The study of chemistry may be different from anything else you have ever done.
Basic chemistry is a survey course in chemistry (that is, it covers a little bit of everything) with emphasis on common chemicals and study techniques. The aim is to give you some chemical and general scientific literacy rather than train you to be a chemist. This outline is to: (a) tell you what to expect in most courses, (b) show you some methods of study for the course, and (c) show you some directions you can turn to for help, if you need it.
The most useful advice is to stay up with or ahead of the class. As the Red Queen said to Alice, “Now, here, you see, it takes all the running you can do, to keep in the same place. If you want to get somewhere else, you must run at least twice as fast as that!” If you fall significantly behind in basic chemistry, it is hard to catch up, but catching up is the only way to continue. The material “snowballs” in this course. By that I mean that the basic facts that need to be learned or memorized at the beginning are going to be used later in the course. Fluency in the basic material is necessary for you to be able to understand and learn the more complex ideas in the course.
Act as if you will have a quiz every class period. These quizzes would either ask you to memorize some basic material or to use some of the material in a math process or a basic idea about chemistry. Designing and giving yourself quizzes to help you schedule your studying will prepare you for the major tests. There are quick quizzes on the web for many of the rote memory items in chemistry.
If you are studying with someone, teach it to each other. The teacher always learns more than the student. (If you have it together sufficiently well to present it to someone else, you know it a lot better.)
Many students find studying with others from the same class is a lot of help. If you get together in a group of three or four, you will always have someone to study with. If you study with other students, it is easier to contact them for missed assignments if you must be out.
General Chemistry Information
This page contains a LOT of information that you’ll need for general chemistry.
Everything from an ion list to solubility rules, and more! That’s right, we’ve put
all the important info on one page, easy for you to access.
Basic Units of Measure
| What I’m Measuring | What Units I Use |
| Length | Meter |
| Mass | Kilogram |
| Time | Second |
| Temperature | Kelvin |
| Amount of Substance | Mole |
| Electrical Current | Ampere |
| Luminous Intensity | Candela |
Solubility Rules
1. Salts containing Group I elements are soluble (Li+, Na+,
K+, Cs+, Rb+). Exceptions to this rule are rare.
Salts containing the ammonium ion (NH4+) are also soluble.
2. Salts containing nitrate ion (NO3–) are generally soluble.
3. Salts containing Cl–, Br–, I– are generally
soluble. Important exceptions to this rule are halide salts of Ag+, Pb2+,
and (Hg2)2+. Thus, AgCl, PbBr2, and Hg2Cl2
are all insoluble.
4. Most silver salts are insoluble. AgNO3 and Ag(C2H3O2)
are common soluble salts of silver; virtually anything else is insoluble.
5. Most sulfate salts are soluble. Important exceptions to this rule include BaSO4,
PbSO4, Ag2SO4 and SrSO4 .
6. Most hydroxide salts are only slightly soluble. Hydroxide salts of Group I elements
are soluble. Hydroxide salts of Group II elements (Ca, Sr, and Ba) are slightly
soluble. Hydroxide salts of transition metals and Al3+ are insoluble.
Thus, Fe(OH)3, Al(OH)3, Co(OH)2 are not soluble.
7. Most sulfides of transition metals are highly insoluble. Thus, CdS, FeS, ZnS,
Ag2S are all insoluble. Arsenic, antimony, bismuth, and lead sulfides
are also insoluble.
8. Carbonates are frequently insoluble. Group II carbonates (Ca, Sr, and Ba) are
insoluble. Some other insoluble carbonates include FeCO3 and PbCO3.
9. Chromates are frequently insoluble. Examples: PbCrO4, BaCrO4
10. Phosphates are frequently insoluble. Examples: Ca3(PO4)2,
Ag3PO4
11. Fluorides are frequently insoluble. Examples: BaF2, MgF2
PbF2.
Types of Reactions
The following is a list of general types of reactions that occur in chemistry.
1. Single Displacement reactions
Form: AB + C –> A + CB
2. Double Displacement reactions
Form: AB + CD –> AD + BC
3. Precipitation reactions
Form: can be single or double displacement reactions (see above) that produce a
solid. Sample forms are:
AB + C –> A (s) + CB or AB + C –> A + CB (s) (single displacement)
AB + CD –> AD + BC (s) or AB + CD –> AD (s) + BC (double displacement)
4. Combustion
Form: CxHy + O2 –> CO2 + H2O
+ energy
5. Acid/base reactions
Form: acid+ + base– –> salt + water
6. Redox reactions (Oxidation-reduction reactions)
Form: X –> X+ + e– (oxidation)
Y + e– –> Y– (reduction)
Ion List
Monatomic Ions
| Symbol | Name | Alternate Name (for variable ions) |
| Al3+ | Aluminum ion | |
| Ba2+ | Barium ion | |
| Be2+ | Beryllium ion | |
| Ca2+ | Calcium ion | |
| Cs+ | Cesium ion | |
| Cr2+ | Chromium(II) ion | Chromous |
| Cr3+ | Chromium(III) ion | Chromic |
| Co2+ | Cobalt(II) ion | Cobaltous |
| Co3+ | Cobalt(III) ion | Cobaltic |
| Cu+ | Copper(I) ion | Cuprous |
| Cu2+ | Copper(II) ion | Cupric |
| Au+ | Gold(I) ion | Aurous |
| H+ | Hydrogen ion | |
| Fe2+ | Iron(II) ion | Ferrous |
| Fe3+ | Iron(III) ion | Ferric |
| Pb2+ | Lead(II) ion | Plumbous |
| Pb4+ | Lead(IV) ion | Plumbic |
| Li+ | Lithium ion | |
| Mg2+ | Magnesium ion | |
| Mn2+ | Manganese(II) ion | Manganous |
| Mn3+ | Manganese(III) ion | Manganic |
| Hg22+ | Mercury(I) ion | Mercurous |
| Hg2+ | Mercury(II) ion | Mercuric |
| Ni2+ | Nickel(II) ion | Nickelous |
| Ni4+ | Nickel(IV) ion | Nickelic |
| K+ | Potassium ion | |
| Ra2+ | Radium ion | |
| Rb+ | Rubidium ion | |
| Ag+ | Silver ion | |
| Na+ | Sodium ion | |
| Sr2+ | Strontium ion | |
| Sn2+ | Tin(II) ion | Stannous |
| Sn4+ | Tin(IV) ion | Stannic |
| Zn2+ | Zinc ion |
Polyatomic Ions
| Element | Symbol | Name |
| Boron ions | BO33- | Borate |
| — | B4O72- | Tetraborate |
| Bromine ions | BrO3– | Bromate |
| — | BrO– | Hypobromite |
| Carbon ions | CO32- | Carbonate |
| — | HCO3– | Hydrogen carbonate or bicarbonate |
| — | C2H3O2– or CH3OO– | Acetate |
| — | C4H4O62- | Tartrate |
| Chlorine ions | ClO3– | Chlorate |
| — | ClO2– | Chlorite |
| — | ClO– | Hypochlorite |
| — | ClO4– | Perchlorate |
| Chromium ions | CrO42- | Chromate |
| — | Cr2O72- | Dichromate |
| Iodine ions | IO4– | Periodate |
| — | IO3– | Iodate |
| — | IO– | Hypoiodite |
| Magnesium ion | MnO4– | Permanganate |
| Nitrogen ions | CN– | Cyanide |
| — | NO3– | Nitrate |
| — | NO2– | Nitrite |
| — | NH2– | Amide |
| — | NH4+ | Ammonium |
| Oxygen ions | OH– | Hydroxide |
| — | O22- | Peroxide |
| — | C2O42- | Oxalate |
| — | HC2O4– | Hydrogen oxalate or Binoxalate |
| Phosphorous ions | PO43- | Phosphate |
| — | PO33- | Phosphite |
| — | HPO42- | Hydrogen phosphate |
| — | H2PO4– | Dihydrogen phosphate |
| Sulfur ions | SO32- | Sulfite |
| — | SO42- | Sulfate |
| — | HS– | Hydrogen sulfide |
| — | HSO4– | Hydrogen sulfate or Bisulfate |
| — | HSO3– | Hydrogen sulfite or Bisulfite |
| — | S2O32- | Thiosulfate |
| — | SCN– | Thiocyanate |
Your Personal Learning Style Management
Learning is easy for some people. They can read something or hear something and understand it. For others, the number of useful learning methods is more limited. Just because a person has a limited way to easily learn DOES NOT MEAN THE PERSON IS STUPID OR UNEDUCABLE. The term LD (learning disability) indicates that a person has a difficult time acquiring and learning information by one source or another. It is truly unfortunate that a small number of students have used the idea of a learning disorder to attempt to cover for laziness. Most of the students who have a learning disorder would dearly love to be like other students, but they have experienced disappointment after disappointment.
If you have a learning disorder, you must analyze (or have analyzed) exactly what it is and learn your best way to compensate for it. Anyone teaching for any time has seen the student who will obey a spoken request, but when asked to read the request will appear to let it go in one eye and out the other. For some people the written word just does not register in the right way. For this type of learning disorder a student might find that reading the assignment aloud from the book will help. For others, copying the words in the book works best. For students who have a rough time understanding oral lectures, (Ask the teacher first.) you might bring a recorder to school and preserve the lecture. At home, speak the lecture after the teacher or transcribe the lecture. Whatever works is best for you.
If you have a problem with learning, you can use these lessons to find some ways you can adapt to learning these various types of material. Particularly the students who want to go into any type of scientific work will see this material again along with the need to grasp great amounts of it quickly. So the basic chemistry course makes a good practice ground for whether you can adapt yourself to this type of study. You know yourself best, so the person to help you with learning problems best is yourself. You need to vary your learning techniques for you for each type of studying. Try a number of methods. Use varying techniques. If teaching chemistry to your little sister works for you, do it. If you do not seem to find a way that you can use, consult a counselor who is willing to help you get professional assistance.
How To Study For Tests
The type of test you can expect will, to a certain extent, determine what kind of studying you must do for it. Most instructors will tell you what style of test they will give you.
Objective tests (fill-in-the-blank or multiple choice) likely have the most obvious study methods. Flash card and association techniques are old standards for this type of work. Students working in pairs can quiz each other on this type of material. Make lists when you need to. Be sure you understand definitions rather than just memorizing them.
Math tests require the information of the objective tests and the practice in working problems. Historically in this course, the majority of trouble with math comes not from the math itself, but with background information that is lacking. Many times your instructor will suggest a problem solving technique to you. Learn it and use it. If your instructor does not suggest a problem solving technique, these lessons have several approaches you can use.
Essay questions require yet another set of skills. The questions contain words like “explain” or “describe” or “compare” and you will be expected to write an essay on the subject at the test. The first requirement, of course, is that you be able to write in the English language. Without intending to be unfriendly or mean, do know that there may be some who have difficulty with that. The best I can tell you for a problem with the English language is that practice definitely shows.
Some students are used to writing a large amount of filler on essay tests. Most instructors can easily see through that and do not grade it, except downward if it becomes excessive. Most instructors look for content when they grade an essay test. Essay answers may be expected to contain information from the book and/or from lecture. To study for essay tests, you should: (a) consider some of the likely questions you might have, (b) collect information, (c) organize the information into an answer, (d) compare your answer to some of the answers of your classmates, and (e) practice answering the questions at home as if you were at the test. You should memorize important items you need to mention (“key words”), but usually efforts to memorize whole answers word-for-word do not work well.
If you still need help, other students in your class may be able to help you. If you do not get the help you need from students, call or visit your instructor. Many professors have “office hours” posted for just such student consultation visits. If the other students cannot help you, maybe they also need some help. Most instructors would be glad to help you on an individual or group basis. ASK. Get help far before you find yourself close to failing. Many instructors understandably feel uncomfortable about helping students with their work only a few hours or minutes before a test. Usually they have test materials to get together at that time and feel a panicky student is not likely to learn much at short notice.
The Ebbinghaus forgetting curve (and the research that followed it) is a milestone of cognitive theory that has been the most effective in helping people learn with the most efficiency. The idea behind it is that as time progresses, the memory of information decreases unless some reminder is accessed. When regular reminders are practiced, the information becomes more solidly entrenched. It is important that the material be learned correctly the first time, but the material will be retained much longer if it is reviewed regularly. Further research shows that material is learned best when it is tied in with other material. Learning meaningless words, for instance definitions that you don’t understand, is not very effective at all. Learn ideas by understanding rather than just by rote memory if you can.
What does this mean for you? That depends on how you learn and what your base of knowledge is. How could you use this? You will have to adapt the idea to your lifestyle. Let me give you an example that you might practice to develop efficient learning.
Let’s say you have a test with little or no math scheduled for a week away. Gather your information for the test and go over it in the way that suits you best until you have a good grasp of the material. Make a list of the things you need to know for the test. Every night (or every other night) before the test, review the material for no more than 15 minutes, preferably before you go to sleep. Let’s say you are learning about acids and bases and that you know some German. You learn the definition of an acid to include that acids taste sour. AHA! The word for acid in German is sauer, pronounced the same way the English word sour is said. You see that sauerkraut just means acid cabbage. You remember that candy sour balls are made with the taste of citrus and that citrus gets some of its flavor from citric acid. With these ideas, you have sealed in the idea that acids are sour.
Take the test and analyze the answers when you get it back. Based on how well you do on tests by studying this way and your personal situation, you may have to change the routine some to adapt to your own needs. Hopefully, you will be pleasantly surprised at how well you know the material and how easy studying was.
Math work sometimes takes a little different approach. There is some background information with math that has to be known. You can learn the background material by rote and then do the math, or you can have the background material with you as you practice the math and then make sure you have memorized the background material and perfected the math process for the test. Make sure you understand the steps in the calculations and the reason for each step.
A good example is the Dimensional Analysis (DA) or Unit Conversion. In order to do the conversions, you need the definitions. To change from grams to kilograms, you need to know the definition that 1 kg = 1000 g. Instead of reviewing material as you would for other material, you should learn the idea and then practice the math for short times spread out far in advance of when you need it.
Class Management
Each course and instructor is somewhat different. Your instructor should give you a course syllabus, a description of the course with information on what you need to do to pass the course. Keep your course syllabus as the first page of your class notebook. This may sound somewhat compulsive, but a well-kept notebook can be a great help to you. Keep all your notes in a three-ring or other insertable binder. Everything pertaining to the course should go into the notebook, preferably in date order.
Taking class notes is another important art. You must be able to judge what is important enough to write in your notes. If you are too busy writing notes, you may miss something useful. If you have trouble taking notes, you should compare your notes with the notes of other students in the same class as soon after the class as you can.
If you need help or information (notes or assignments) in the course, your first questions should go to the members of your lab or study group. Next, ask other students in the class. Get the name and phone number or email address of the members of your lab group and other students in the class. Keep these in your notebook. Contact them when you need guidance about course requirements.
Some colleges or universities have teaching professors who only lecture and TA’s (teaching assistants) who will do the “dirty” work of consulting with students in small groups, give quizzes, and grade tests. Most lecturing professors will stick to the material in the course, but, since the classes are large, do not take questions during the class. You need to rely on your TA for help in the class.
Some colleges and universities allow you to drop a course before the end of it to preserve your grade average. If for some reason you need to drop out of the course, give your instructor the courtesy of the opportunity to talk with you. There are some good reasons for wanting to drop out; you don’t feel you have the background, you don’t have the time to devote to the work, you have other turmoil in your life and can’t expend the emotional or mental effort, your work schedule conflicts with your school, etc.
Some Pointers On Studying For Chemistry
- Keep up with the course. Catch up as quickly as you can if you fall behind.
- Understand all concepts before going on.
- Thoroughly memorize all background material you are assigned.You will need it later.
- Keep a list of emergency contacts if you have problems. Get the names, telephone numbers, email addresses, social network connections, etc of the teacher, other students in the class, your TA. and other sources of help. Make a list of websites that could be of help.
- Keep a close watch on the assignments for the course. Contact other students first if you must rather than bothering the teacher.
- Find a good place to study. It must be comfortable, quiet, well-lit, and have all the things you need.
- Find a good consistent time for studying chemistry.
- Review lectures as soon afterward as you can. Cognitive studies show that people remember better when the information is fresh in mind.
- Determine which study methods are best for you.
- Shape your lifestyle around the requirements of the course.
- Study with others if it helps you. Choose study partners who are serious about learning.
Problem Solving Skills In Chemistry
In general, accuracy needs to increase rather than speed. Any technical literature is concentrated, and any form of “speed reading” is a waste of time on informationally dense material. Instead, devices to increase comprehension are necessary, such as mental models, finger counting, lip movement, or figure drawing. If you don’t learn how to slow down and learn the material, reading the textbook is a waste of time. Some other ways to slow down and carefully consider the words include reading aloud to yourself, reading or explaining to another person, or writing the information. If you write the information, don’t just copy it. Put it into your own words and go back to see if it makes sense.
Intelligence may be defined as the ability to do abstract reasoning. Weaker students jumble abstract reasoning from lack of ability to grasp the entire problem at “one shot.” The next step for a weaker student is to give up for lack of a way to even get started. The best students support abstraction with concrete ideas. It is not the ability of the better student to fully grasp the complete abstraction that sets them apart, but the ability to organize a problem so that no part is too difficult to solve. The idea behind the abstraction becomes more apparent as the idea is used. Another way to put that is that the better student does not usually have more efficient mental “hardware” but better “software.”
One tool for the development of better methods of problem solving is to take a short standard intelligence test and later analyze the results. The number of correct answers is not the most important data, but the analysis of how to “concrete” each question and how to spot potential errors on a case-by-case basis can help students see some ways to improve their personal analytical reasoning ability.
The use of a standardized test will give an ability to see a broad general group of problems that are each “informationally neutral”, that is, having no need for a body of background information other than the very rudimentary, such as the number system, the alphabet, and the ability to define words. Indeed, on any IQ test some questions require just word definition knowledge. In coursework, though, a body of knowledge is needed to interpret the questions. In chemistry some of this material may have to be known by rote in order to most efficiently perform on tests. Some examples of material that should be know by rote are the symbols of elements, polyatomic ions, some valences, measurements and the conversion factors among them, dimensions and the symbols for them, and some common names for materials. There are several ways to learn rote material, to include flashcards, pair quizzing, mnemonic devices, and reading aloud. Class time is poorly spent on rote material, but it is the teacher’s responsibility to point out which material is a candidate for rote learning. There is, unfortunately, no way to “pour” this information into a student. That basic maturity of recognizing something that must be done and doing it is necessary as a prerequisite.
We say that the math is difficult for the students, but they can do the arithmetic very well on the calculators they have. The real stumbling blocks are difficulties organizing the problem and a lack of background rote information. The problem-solving technique needs to be practiced first with trivial problems and then with increasingly difficult problems. “Practice makes perfect” seems to be true; the best way to learn what can go wrong in a problem is to make the mistake yourself, find the mistake, and learn from your mistake. Again, from the initial observations, any problem that can not be thought out completely in the head needs an overall “mental roadmap” toward a solution and an orderly implementation of the pathway in which each step is demonstrable.
For chemistry problems involving a formula, one pathway is the W5P method to be introduced later. For most conversion problems (many of the chemistry problems), the Dimensional Analysis system, also to be introduced later, is a splendid framework. The point is that with a good framework in which to think of the problem, a complicated problem is merely a series of simple problems.
Some More Useful Pointers On Chemistry Problem Solving
- Read the problem carefully, moving your lips if necessary.
- Find the best way to think of the problem in the most concrete terms.
- Draw the problem, if possible.
- In chemistry example problems list the important information items in the problem. Show GIVEN, the information you know about the problem labeled with its units and symbols and FIND, what you need to find in the problem.
An example:
FIND: D (density)
GIVEN: V = 46.9 mL m = 127.1 g (V is volume and m is mass.)
Show the formula from the symbols in GIVEN and FIND (D = m/V)
- Know the background material for the problems.
- Follow the problem-solving method your teacher gives you, if one is given.
- Understand and use the units of quantities.
- Know your own weakest points so you can be wary of them.
- Go back and check your work. Use the units of the measurements to check your work. If the answer does not make sense, something is wrong.