www.mindbites.com In this lesson, you will learn how to convert measurements from one unit to another. You will learn how to create a conversion factor, which is always a factor of one that is constructed from a known quality. When creating a conversion factor, you will want to make sure to choose one that allows you to cancel out unwanted units. Prof. Yee also discusses significant figures when using conversion factors. Since conversion factors are considered exact, they have an infinite number of significant figures that are not limited. The data will limit the number of significant figures that you will use in an answer. Objects that are counted are also considered exact with unlimited significant figures. You will learn how to link multiple conversion factors, which is sometimes necessary when converting from one unit to another. Prof. Yee reminds you to make sure you always “”take the units along for the ride”" to ensure that you are finding your answer in the proper units. Finally, you will learn the proper conversion factors for converting both from degrees Farenheit to degrees Celsius and from degrees Celsius to degrees Kelvin. 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 …
Chemistry: Dimensional Analysis
Chemistry: Describing Chemical Formulas
www.mindbites.com In this lesson, you will learn the common nomenclature of chemistry. Professor Harman defines and contrasts atoms, molecules, ions, and ionic salts/covalent solids. Then Professor Harman covers written chemical formulas and visual representations of molecules. A molecular formula is a chemical formula that represents the actual number of atoms of each element within a molecule. An empirical formula is a chemical formula of a compound written with the smallest integer ratio of subscripts. Empirical formulas are always used to describe ionic compounds and covalent network solids. Various visual representations of molecules include the ball and stick three dimensional model that closely represents the structure of the molecule, a line drawing that approximates the structure in two dimensional terms, and a shorthand often used by organic chemists. Professor Harman warns that molecules are defined by their unique arrangements of atoms, and a formula can represent many different molecular compounds (known as isomers). 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 …
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: The Concept of Equilibrium
www.mindbites.com Professor Harman explains the concept of equilibrium. In a dynamic equilibrium, though appearing static at the acroscopic level, the forward reaction equals the reverse reaction. To create this type of equilibrium, the system must be closed. This can occur in a chemical system, as well. In chemical equilibrium, the forward and reverse reactions are equal and the concentrations of products and reactants do not change. Professor Harman also explains how you can determine the direction of equilibrium mathematically. To do this, you can look at the partial pressures. As the pressures level out, the system reaches equilibrium. You can also look at the rates of the forward and reverse reactions. When the rates become equal, the system has reached equilibrium. Then, Professor Harman explains that if the equilibrium is disrupted, a new equilibrium will establish in which the overall ratios pf products and reactants are equal. These ratios help to determine the Equilibrium Constant, which reveals the direction of the overall balance of the chemical system. 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 …