Chemistry: Balancing Chemical Equations


www.mindbites.com Professor Yee walks you through the process of determining a balanced equation from an unbalanced chemical equation using a method called Balancing by Inspection. There are no hard and fast rules for this method, but Prof. Yee gives you several tips and multiple examples. The first tip Prof. Yee gives you is to start with the molecule or compound that is the most chemically complex. If there is not one compound that stands out, he recommends beginning with the first chemical compound in the equation, as it is generally the one that is being reacted on. He recommends that you leave any pure elements for last. Due to convention, all of the coefficients in a balanced chemical equation must be whole numbers, so Professor Yee shows you how to adjust an equation by multiplying through by the least common multiple. Finally, he reminds you that the number of atoms of each element in the equation must be balanced both on the reactant side and the product side of the equation. Taught by Professor Yee, this lesson was selected from a broader, comprehensive course, Chemistry. This course and others are available from Thinkwell, Inc. The full course can be found at www.thinkwell.com The full course covers atoms, molecules and ions, stoichiometry, reactions in aqueous solutions, gases, thermochemistry, Modern Atomic Theory, electron configurations, periodicity, chemical bonding, molecular geometry, bonding theory, oxidation-reduction reactions, condensed phases

Chemistry: The Scientific Method


www.mindbites.com This lesson uses a simple experiment of burning different substances to help explain the Scientific Method and to associate the process to the Scientific Hierarchy, the formulation of the Law of Conservation, and the beginning of modern chemistry. The Scientific Method is the process used to organize and test the observations about the world that are made during experimentation. This method starts with observation and experimentation. Then, patterns, trends, and laws are found in the observations. These help us to formulate hypotheses, which either lead to the formulation of theories or further experimentation and observation. Often, hypotheses will need to be revised, when newer observations conflict. The Scientific Method has led to a Scientific hierarchy of laws, hypotheses, and theories, which are defined in this lesson. This process also led to the birth of modern chemistry, when Dalton formulated the 5 Atomic Theory Postulates from Lavoisier’s Law of the Conservation of Matter. Taught by Professor Gordon Yee, this lesson was selected from a broader, comprehensive course, Chemistry. This course and others are available from Thinkwell, Inc. The full course can be found at www.thinkwell.com The full course covers atoms, molecules and ions, stoichiometry, reactions in aqueous solutions, gases, thermochemistry, Modern Atomic Theory, electron configurations, periodicity, chemical bonding, molecular geometry, bonding theory, oxidation-reduction reactions

Chemistry: Precision and Accuracy


www.mindbites.com In this lesson, Prof. Yee discusses precision and accuracy in measurements. He explains that all measurements will have a degree of uncertainty due to instrumentation, and the range of uncertainty will appear in the last digit of the measurement. You want to have measurements that are both precise and accurate. Precision is the reproducibility of the measurement of a quantity and is tied to the concept of random error. Prof. Yee uses a ruler as an example of precision. Accuracy refers to how close a measurement is to a hypothetical true value. It is possible for a measurement to be precise but not accurate if there is a systematic error. Systematic error is an error inherent to the measurement of a value, such as a clock that is consistently 5 minutes fast. Finally, Prof. Yee explains the relationship between precision and accuracy using a game of darts. Taught by Professor Yee, this lesson was selected from a broader, comprehensive course, Chemistry. This course and others are available from Thinkwell, Inc. The full course can be found at www.thinkwell.com The full course covers atoms, molecules and ions, stoichiometry, reactions in aqueous solutions, gases, thermochemistry, Modern Atomic Theory, electron configurations, periodicity, chemical bonding, molecular geometry, bonding theory, oxidation-reduction reactions, condensed phases, solution properties, kinetics, acids and bases, organic reactions, thermodynamics, nuclear chemistry, metals, nonmetals

Chemistry: Naming Cations & Understanding Nomenclature


www.mindbites.com Naming chemical compounds can be tricky, and requires a little bit of knowledge about the trends and naming conventions. First, Professor Harman explains that how you name a compound will depend on the type of compound – whether it is an ion, molecular compound, acid, or base. For ions, the way you name the ion will depend on whether the compound is a cation or anion and whether or not it is monatomic, polyatomic, or a transition metal. Anions follow slightly more difficult naming conventions. Molecular compounds use Greek prefixes and will always start with the element furthest from Fluorine. Some molecular compounds have common names (such as water), and these are always used. Bases are simply named like ionic materials. Acids are named based on the suffix of the anion they are derived from. If the anion ends in -ate, the acid uses an -ic suffix. If the anion ends in -ite, the acid uses an -ous suffix. Taught by Professor Harman, this lesson was selected from a broader, comprehensive course, Chemistry. This course and others are available from Thinkwell, Inc. The full course can be found at www.thinkwell.com The full course covers atoms, molecules and ions, stoichiometry, reactions in aqueous solutions, gases, thermochemistry, Modern Atomic Theory, electron configurations, periodicity, chemical bonding, molecular geometry, bonding theory, oxidation-reduction reactions, condensed phases, solution properties, kinetics, acids and bases, organic reactions

Chemistry: Basic Buffers


www.mindbites.com This lesson was selected from a broader, comprehensive course, Chemistry, taught by Professor Harman, Professor Yee, and Professor Sammakia. This course and others are available from Thinkwell, Inc. The full course can be found at www.thinkwell.com The full course covers atoms, molecules and ions, stoichiometry, reactions in aqueous solutions, gases, thermochemistry, Modern Atomic Theory, electron configurations, periodicity, chemical bonding, molecular geometry, bonding theory, oxidation-reduction reactions, condensed phases, solution properties, kinetics, acids and bases, organic reactions, thermodynamics, nuclear chemistry, metals, nonmetals, biochemistry, organic chemistry, and more. Dean Harman is a professor of chemistry at the University of Virginia, where he has been honored with several teaching awards. He heads Harman Research Group, which specializes in the novel organic transformations made possible by electron-rich metal centers such as Os(II), RE(I), AND W(0). He holds a Ph.D. from Stanford University. Gordon Yee is an associate professor of chemistry at Virginia Tech in Blacksburg, VA. He received his Ph.D. from Stanford University and completed postdoctoral work at DuPont. A widely published author, Professor Yee studies molecule-based magnetism. Tarek Sammakia is a Professor of Chemistry at the University of Colorado at Boulder where he teaches organic chemistry to undergraduate and graduate students. He received his Ph.D. from Yale