General Chemistry: A Self-Study Program (Part 2)

General Chemistry (Part 2) starts with the preparation of various types of solutions such as molarity and normality, which is the dissolution of a solid, a liquid, or a gas in a solvent. An example is the dissolution of carbon dioxide in coke cola; the CO2 gas dissolves in the soda water to give solution of known concentration. The solubility of a solute is determined by enthalpy (∆H) and entropy (∆S). Entropy is the measure of disorder in a system. For example, a lived-in house never cleans itself up; therefore, entropy is a positive value, which is assigned the symbol ∆S. On the other hand, enthalpy (∆H) is total internal energy of a system; it is given by equation: ∆E = Q(heat) + P∆V. Sugar dissolves faster in hot water as opposed to cold water. Energy is composed of a heat component and work component, which is P∆V; no work is done when volume is held constant because the change in volume is zero. Therefore, the internal energy of the system is equal to the amount of heat absorbed or released [∆E = ∆H = Q(heat)] during the dissolution of the solute in a solvent such as water. The latter are thermodynamically quantities, which are seen in the 1st and 2nd Law of Thermodynamics. The book continues with single and double displacement reactions and their heats of formation, which is based on thermodynamics quantities such as enthalpy (∆H), entropy (∆S), and Gibbs free energy (∆G). Systems or reactions always proceed to their lowest energy. That is, for a feasible reaction, ∆G is negative, ∆S is positive and ∆H can be positive or negative depending on the reaction. Therefore, chemical reactivity is controlled by two factors; they are thermodynamics and kinetics. Thermodynamics answers the questions such as the stability of the product while kinetic tells how fast the product is produced from the reactants. For example, kinetics tells how fast a reaction will occur; that is, if a reaction takes 100 years, it is not a feasible reaction. Therefore, a reaction must be thermodynamically and kinetically favored; reactions must occur in reasonable amount of time and the energy needed for the reaction must be reasonable. The book covers the states of matter, the gas laws, and electrochemistry; it is used to determine equilibrium constants (Keq), ∆G, and ∆S. The book discusses crystal field theory, which is applied to transition metal complexes. The data gives bond order, magnetic properties; high and low spin metal complexes, and much more including electron configurations. The book ends with a discussion of nuclear chemistry, and an overview of Organic Chemistry. In summary, the book explains the relationship between matter and energy in term of enthalpy (∆H); it is related to internal energy and entropy (∆S), which is a measure of disorder in a system. For example, a cold body never warms on its own without the application of heat energy. If heat is released from a reaction, enthalpy (∆H) is a negative value and entropy (∆S) is positive; such a reaction is favorable and is likely to occur as written. You will learn how to calculate thermodynamic quantities; interpret them in terms of reaction theory. You will solve problems based on thermal data, and predict the outcomes of reactions based on these values. You will be able to tell whether a reaction will or will not occur spontaneously based on the grounds of thermodynamics; this skill will be demonstrated during guided practices and assigned problems. You should solve all problems as they are presented in the book, this includes guided practices, and those presented at the end of each chapter. The problems should be solved before looking at the answers; otherwise, you will not learn the techniques of problem solving as intended. Good Luck!