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Thursday 8 June 2017

GENERAL CHEMISTRY

Requirements

What you need to know

Dartmouth's Department of Chemistry offers two separate sequences in general chemistry. A majority of our students are enrolled in Chemistry 5-6. In addition, there is a fall-term honors section, Chemistry 10, available only to especially well-prepared First Year students.
Each year we enroll quite a number of students who have not had high school chemistry or who feel that their high school chemistry backgrounds are weak. It is most certainly possible for such students to do well in general chemistry at Dartmouth. However, many of them find it helpful to study and review in preparation for the course. This page will tell you what you need to learn or review to be off to a flying start in general chemistry.

A Self Test

If you would like to try a few real-world problems to measure your preparation and skills in the fundamental areas discussed in more detail below, please feel free to download the Chemistry 5 Self Test (a 3-page pdf file). This test (which carries neither credit nor penalty) is entirely for your private use. It has ten straighforward problems spread across the topics listed below. Work your way through it at your own pace, but try to solve each problem without consulting any other reference. Once you have come up with your best answers to these problems (or have decided that you cannot work one or more problems on your own), then, and only then, you should download the 9-page pdf Self Test Solutions, which gives fairly detailed, step-by-step answers to each of these problems. The page on this site titled Dimensional Analysis and Units will also provide some review on those topics, and your course text probably has helpful sections as well.
There is no "passing or failing grade" on this test. Rather, it is meant to show you what areas you may need to review, study in more depth, or continue to practice.

The Important Basic Topics

Listed below are some of the more important topics that you should be familiar with. You may, of course, review or study as much as you like, but you are encouraged to concentrate on and become familiar with the following topics:
1. Metric System. Be familiar with the units of mass, length, and volume in the metric system. A separate page covers this important topic.
2. Temperature Scales. Be familiar with the Celsius (centigrade) and the kelvin (absolute) temperature scales.
3. Symbols of the Elements. You should be familiar with the symbols for elements with atomic numbers 1-38, 46-56, and 78-83. The symbols are usually abbreviations of either the English or Latin name of the element. Although you will have a periodic table for all exams, the more familiar you are with the symbols, the better off you will be.
4. Chemical Formulas. You should become familiar with the way in which the symbols of elements are combined to give chemical formulas for neutral (uncharged) molecules and positive or negative ions, such as SiCl4, CaF2, SO4-2, etc.
5. Chemical Equations. You should understand how chemical formulas are combined to give chemical equations, which describe chemical changes.
6. Atomic Structure. You should have at least a rough idea of the structure of the atom. Be aware that the nucleus, composed of protons and neutrons, is the massive (but tiny) positively charged central core of the atom. It is surrounded by one or more negatively charged electrons which occupy most of the volume of the atom but contribute only a tiny fraction of its mass. You should also know what isotopes are.
7. Weight Relationships. You should know what atomic number, atomic mass number, atomic weight, formula weight, and molecular weight mean. Understand what gram atomic weight, gram formula weight, and gram molecular weight mean. Know what is meant by a mole of a substance, and understand the relationship between the mole and Avogadro's constant.
8. Concepts from Physics. Have some notion of the meaning of force and energy and the units in which they are measured in the Standard International (SI) system of units. Pressure is a measure of force per unit area; common units of pressure are pascal (Pa), atmosphere (atm), and torr (Torr).
9. Concentrations. Know some common ways of expressing concentration, such as weight percent and moles of solute per liter of solution (molarity).
Review these topics, and check out the page covering Dimensional Analysis and Units.
A review of certain topics in high school mathematics will also be valuable to any student in college chemistry. Listed below are some of the topics with which you should be quite comfortable. The last two, numbers 6 and 7, apply more to Chem 6 than Chem 5.
1. Calculators. You must have a calculator and know how to use it for multiplication, division, taking square roots, finding logarithms and antilogarithms (both base-10 and natural, or base-e, logs), and using exponential notation.
2. Exponential Notation. Be thoroughly familiar with exponents, and be able to multiply, divide, raise to powers, and take roots of numbers with exponents. Understand the relationship between exponents and logarithms, and be able to work with logarithms, both base 10 and base e. Know the SI prefixes for common multiples of powers of 10, such as "m" for "milli-" or "k" for "kilo-" and so forth.
3. Linear Equations. Be able to recognize an equation for a straight line, and know how to recognize the line's slope and intercept in the equation.
4. Algebra. Be able to solve a system of two simultaneous linear equations in two unknowns.
5. More Algebra. Be able to solve a quadratic equation.
6. Trigonometry. Be familiar with angles measured in radians as well as in degrees, and understand and be able to work with the basic trigonometric functions: sine, cosine, and tangent.
7. Coordinate Systems. Be familiar with polar coordinate systems in two and three dimensions as well as the common Cartesian (x,y) coordinate system.
Many of the definitions and concepts mentioned above will be reviewed quickly during the initial weeks of Chemistry 5. However, it will be to your advantage to have seen such material and thought about it in advance. You will also find most of these topics are included in the first chapters or appendices of your textbook. If you find that the text selected for your course assumes too much previous knowledge, try reading another textbook. Instructors generally make a variety of books available at the reserve desk at Kresge Library, and you may find one that is more clear to you, especially if you have not previously studied chemistry at this depth before.
For further details log on website :
https://www.dartmouth.edu/~genchem/know.html

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