San Antonio College Library

In this video lesson, Paul Andersen explains that elementary reactions are steps within a larger reaction mechanism. Colliding molecules require sufficient energy and proper orientation to break bonds and form new bonds. A unimolecular reaction mechanism requires one type of reactant and is a first-order reaction. A bimolecular reactions requires two molecules colliding and is a second-order reaction. Termolecular reactions are rare but are the colliding...

In this video lesson, 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 of an anylate can be determined through both gravimetric analysis and a titration.--Publisher.

In this video lesson, 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 formed. The rate constant is temperature dependent. The Arrhenius equation can be used to calculate the activation energy when the temperature and rate constant are calculated.--Publisher.

Starting with a definition of reversible reactions, this program covers the basic concepts of chemical equilibrium and the equilibrium law. The concept of equilibrium is illustrated by comparison to the movement of cars in and out of a parking lot, the motion of a person walking the opposite way on a moving walkway, and the movement of people on and off paddleboats. The video concludes by considering what an equilibrium constant indicates about a...

This program heats things up with a concentrated analysis of thermochemistry, explaining precisely how temperature figures into chemical reactions. Section one covers endothermic and exothermic reactions, the standard enthalpy of formation, and the workings of Hess's Law, while section two explains the concepts of heat capacity, molar heat capacity, and specific heat.

Chemical changes occur around us, and inside us, all the time. When chemical reactions happen, one or more new substances are formed and energy is either given off or absorbed in the process. Spontaneous chemical reactions, those that occur naturally under favorable conditions release free energy, meaning they are exergonic. Endergonic reactions, by contrast, require net energy input to make the reaction happen. This resource explores energy associated...

In this video lesson, Paul Andersen explains how equilibrium is achieved in a reversible reaction. When the rate of the forward reaction is equal to the rate of the reverse reaction, the system is at equilibrium. Graphical analysis of equilibrium is included along with a walkthrough of several calculations.--Publisher.

In this video lesson, 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 the equilibrium constant. If the temperature is changed, a new equilibrium constant will be established.--Publisher.

In this video lesson, Paul Andersen defines the rate of a reaction as the number of reactants that are consumed during a given period of time. The rate of the reaction can be affected by the type of reaction as well as the concentration, pressure, temperature, and surface area.--Publisher.

In this video lesson, Paul Andersen explains how the rate law can be used to determine the speed of a reaction over time. Zeroth-order, first-order, and second-order reactions are described as well as the overall rate law of a reaction. The rate of a reaction can be determined experimentally.--Publisher.