Oxidation-Reduction Reactions Some General Principles

You are given the four solids, K2CO3, CaO, ZnS04, and BaCOa, and three solvents, H20(I), HCI(aq), and H2S04(aq). You are asked to prepare four solutions, each containing one of the four cations, that is, one with K (aq), one with Ca (aq), and so on. Using water as your first choice, what solvent would you use to prepare each solution Explain your choices. 

Practical applications of oxidation-reduction reactions can be traced back thousands of years to the period in human culture when metal tools were first made. The metal needed to make tools was obtained by heating copper or iron ores, such as cuprite (CU2O) or hematite (Fe203), in the presence of carbon. Since that time, iron has become the most widely used of all metals and it is produced in essentially the same way by heating Fe203 in the presence of carbon in a blast furnace. A simplified chemical equation for the reaction is given below. 

Definitions of oxidation and reduction based solely on the transfer of O atoms are too restrictive. By using broader definitions, many reactions can be described as oxidation-reduction reactions, even when no oxygen is involved. 

Suppose we rewrite equation (5.17) and indicate the oxidation states (O.S.) of the elements on both sides of the equation by using the rules listed on 

of oxygen is —2 everywhere it appears in this equation. That of iron (shown in red) changes. It decreases from +3 in Fe203 to 0 in the free element, Fe. The O.S. of carbon (shown in blue) also changes. It increases from +2 in CO to -1-4 in CO2. In terms of oxidation state changes, in an oxidation process, the O.S. of some element increases in a reduction process, the O.S. of some element decreases. 

---

Distinguish between an electrolyte and a nonelectrolyte, and provide examples of each. 5.2 Use the solubility guidelines tor common ionic solids to determine whether 5-4 Oxidation-Reduction Reactions Some General Principles 5-7 Stoichiometry of Reactions in Aqueous Solutions Titrations... 

Oxidation-Reduction Reactions Some General Principles 167... 

Oxidation-Reduction Reactions Some General Principles— In an oxidation-reduction (redox) reaction certain atoms undergo an increase in oxidation state, a process called oxidation. Other atoms undergo a decrease in oxidation state, or reduction. Another useful view of redox reactions is as the combination of separate half-reactions for the oxidation and the reduction. 

Chapters 15 through 24 explore intermediary metabolism. Chapter 15 opens the topic with chemical principles that provide some unifying themes. Thermodynamic concepts learned earlier in general chemistry and in Chapter 1 are applied specifically to biochemical topics such as coupled reactions. In addition, this chapter explic-idy makes the connection between metabolism and electron transfer (oxidation-reduction) reactions. 

Another type of reaction may be mentioned here, which, while not oxidation-reduction, shows some of the possibilities in the way of relative oxidizing potentials of different atoms, or the relative aflSnities of the atoms for valence electrons. Silver nitrite ind sodiuiii nitrite when treated with an alkyl halide give different products. With the former, a nitro compound is obtained mainly with the latter a nitrite predominates. While according to the older views, this would point to different structures for the two nitrites, according to the principles developed in this book, the explanation of these differences involves tautomerism and several chemical equilibria. The reaction may be given in general terms as follows ... 

You ve heard electrochemistry of corrosion as a lecture I shouldn t spend much time on it but I d like to describe some electrochemical effects for film formers. First the general principles. If you put a good electronic conductor (a metal) in an aqueous solution, you will typically find that an electrical potential is developed between the piece of conductor and the solution. When ions of the metal enter the solution and leave extra electrons behind a negative potential is developed. All oxidation reactions occurring on the surface are expected to produce this result. Similarly, reduction reactions that use electrons from the metal are expected to produce a more positive potential in the metal. The solution potential of the metal influences the rate of an electrochemical half-cell reaction in accordance with Le Chatelier s Principle, so it is possible to predict through the use of the Nernst Equation the potential that will exist when the only significantly rapid reactions are the oxidation and reduction parts of a reversible reaction. When more than one potentially reversible process occurs, the rate of oxidation will be expected to exceed the rate of reduction for at least one and the converse for at least one. At... 

---