Bozeman Science
Conservation of Atoms
In this video Paul Andersen explains how atoms are conserved in a chemical reaction. This can be seen in a chemical equation where the subscripts represent the atoms in the molecule and the coefficients represent the molecules. The mass...
Bozeman Science
Reaction Intermediates
In this video Paul Andersen explains how reaction intermediates are created in elementary steps and may not appear as either a reactant or product. Experimentation is used in Chemistry to identify reaction intermediates.
Bozeman Science
Intermolecular Potential Energy
In this video Paul Andersen explains the importance of intermolecular forces in chemistry. Intermolecular forces exist between dipoles (like hydrogen bonds), between dipoles and induced dipoles (like Ar and HCl) and between induced...
Bozeman Science
Symbolic Representations
In this video Paul Andersen explains how the conservation of matter can be displayed with both symbolic representations and particulate drawings. A simple conservation of matter problem is also included.
Bozeman Science
Kinetic Reaction Control
In this video Paul Andersen explains how a spontaneous process may take either the thermodynamically controlled or the kinetic controlled pathway. If the activation energy determines the path taken then the process is under kinetic...
Bozeman Science
Chemical and Physical Processes
In this video Paul Andersen explains the difference between chemical and physical processes. Chemical processes occur when bonds are broken and reformed. Physical processes occur when intermolecular forces are broken and reformed. A gray...
Bozeman Science
Le Chatelier's Principle
In this video Paul Andersen explains how Le Chatelier's Principle can be used to predict the effect of disturbances to equilibrium. When a reversible reaction is at equilibrium disturbances (in concentration, temperature, pressure, etc.)...
Bozeman Science
Ionic Bonding
In this video Paul Andersen explains how ionic solids form when cations and anions are attracted. When atoms lose or gain electrons they form ions. The strength of the attraction between ions is based on the amount of charge and the...
Bozeman Science
Multistep Reactions
In this video Paul Andersen explains how an overall chemical reaction is made up of several elementary steps. The stoichiometry of this equation can be predicted but the rate law must be measured. If the elementary steps of the reaction...
Bozeman Science
Equilibrium Disturbances
In this video Paul Andersen explains how disturbances to a reversible reaction at equilibrium affect the equilibrium constant and the reaction quotient. For example if the concentration is changed the reaction will move to reestablish...
Bozeman Science
Driving Nonspontaneous Processes
In this video Paul Andersen explains how you can drive non spontaneous processes by adding external energy (like electricity or light) or by coupling it to a spontaneous process (like the conversion of ATP to ADP)
Bozeman Science
Synthesis and Decomposition Reactions
Atoms or molecules combine to form a new compound in a synthesis reaction. Examples include the addition of oxygen to magnesium metal to create magnesium oxide and the addition of carbon dioxide to water to crete carbonic acid. A combine...
Bozeman Science
Chemical Analysis
In this video Paul Andersen explains how chemical analysis is important in determining the composition, purity and empirical formula of a compound. An empirical formula determination problem is also included.
Bozeman Science
Free Energy and the Equilibrium Constant
In this video Paul Andersen explains how thermodynamic and equilibrium reasoning can be related through changes in free energy and the equilibrium constant. When the delta G is negative the reaction shifts to the right or favors...
Bozeman Science
Molecular, Ionic, and Net Ionic Equations
In this video Paul Andersen shows you how to write balanced equations that describe chemical changes. He then gives you a short introduction to balancing equations and uses the PHET site to practice this skill. In aqueous solutions an...
Bozeman Science
Neutralization Reaction
In a neutralization reaction (or acid-base reaction) a proton is transferred from the Brinsted--Lowry acid to the Brinsted--Lowry base. Water is amphoteric and so it can serve as either an acid or a base in a neutralization reaction. The...
Bozeman Science
Mass Spectrometry
In this video Paul Andersen explains how a spectrometer was used to identify the presence of isotopes. This modified Dalton's original atomic theory because atoms of the same element had different masses. The functional parts of a mass...
Bozeman Science
Lewis Diagrams and VSEPR Models
In this video Paul Andersen explains how you can use Lewis Diagrams and VSEPR Models to make predictions about molecules. The Lewis diagrams are a two-dimensional representations of covalent bonds and the VSEPR models show how the...
Bozeman Science
London Dispersion Forces
In this video Paul Andersen describes the positive force intermolecular forces found between all atoms and molecules. As electrons are distributed unevenly it creates instantaneous dipoles which hold molecules together. This force even...
Bozeman Science
Endothermic and Exothermic Reactions
In this video Paul Andersen explains how heat can be absorbed in endothermic or released in exothermic reactions. An energy diagram can be used to show energy movements in these reactions and temperature can be used to measure them...
Bozeman Science
The Reaction Path
In this video Paul Andersen explains how the reaction path can be described in an energy profile. Enough energy must be added to reach the activation energy required and stress the bonds. Eventually the bonds break and new bonds are...
Bozeman Science
Reversible Reactions
In this video Paul Andersen describes how reversible reactions achieve equilibrium as reactants are converted to products and products are converted to reactants. A model shows how forward reaction rates and reverse reactions rates...
Bozeman Science
pH and Buffers
In this video Paul Andersen explains how buffer solutions maintain pH in a solution. A buffer solution is made up of a weak acid and its conjugate base. As strong acids or bases are added the pH remains stable. A good buffer solution has...
Bozeman Science
Ionic Solids
In this video Paul Andersen explains how ionic solids form a lattice between cations and anions. According the Coulomb's Law the lattice energy increases as the ions carry a larger charge and are smaller. Some of the properties of ionic...