In the physical world, every movement to every reaction has a point where equilibrium is established. Chemical equilibrium is the state in which the forward reaction rate and the reverse reaction rate are equal. Sometimes, when a chemical reaction takes place, it continues for a period of time and then seems to stop before all the reactants are consumed. But the reaction does not actually stop. This free online course on physical chemistry discusses the relationship between the concentrations of reactants and products in a reaction at equilibrium. It covers in detail the concept of chemical equilibrium and equilibrium constant expressions. An example of equilibrium is the movement of our bodies running on a treadmill in a forward and backward motion. The course analyzes equilibrium constant expressions when chemical reactions are added, and you will learn about the relationship between equilibrium constant and thermodynamic favorability.

You will find every aspect of chemical reactions and reversible reactions discussed in this course very useful in various laboratory procedures. It is important to understand that not all situations of equilibrium are alike: some chemical reactions favor the production of products at equilibrium. This means that not all of the reactants are converted to products. Other reactions favor the reactants at equilibrium. Once a chemical system has reached an equilibrium state, there are factors that affect equilibrium. The sections that follow explain in detail these factors, which are temperature, pressure and concentration. Le Chatelier’s principle is one of the pivotal ideas in understanding the behavior of a system in equilibrium. In addition, you will learn how to apply Le Chatelier’s principle to the solubility of solids in aqueous solutions as well as to gaseous chemical equilibriums. These problems are solved in an easy step-by-step manner while explaining the best ways to end up at the desired solutions.

Other aspects of physical chemistry covered are acids, bases and salts. Acids and bases play a vital role in our lives. Many foods we eat are either acidic or basic in nature, and our bodies are controlled acid-base systems. This course explains the properties of acids and bases. It describes the concept of Arrhenius acids and Arrhenius bases as well as the Bronsted Lowry acid-base model. How do you identify the strength of an acid? You will learn how to classify weak or strong acids and bases based on pH. You will also learn natural and synthetic indicators. This course explores in detail how to use the Henderson-Hasselbalch equation to calculate the pH of the buffer solution. At the end, you will be able to solve carefully analyzed solubility, chemical reaction and equilibrium constant of water problems from start to finish.