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Lesson declared Oxidation and reduction After finished this lesson student will to able to # Say about the Oxidation # Say about reduction. # Say about.

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Presentation on theme: "Lesson declared Oxidation and reduction After finished this lesson student will to able to # Say about the Oxidation # Say about reduction. # Say about."— Presentation transcript:

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3 Lesson declared Oxidation and reduction

4 After finished this lesson student will to able to # Say about the Oxidation # Say about reduction. # Say about Oxidizing and reducing agents. #Say about Metal displacement.

5 Oxidation and reduction Sodium chloride is formed through the redox reaction of sodium metal and chlorine gas Redox reactions can be understood in terms of transfer of electrons from one involved species (reducing agent) to another (oxidizing agent). In this process, the former species is oxidized and the latter is reduced. Though sufficient for many purposes, these descriptions are not precisely

6 correct. Oxidation is better defined as an increase in oxidation state, and reduction as a decrease in oxidation state. In practice, the transfer of electrons will always change the oxidation state, but there are many reactions that are classed as "redox" even though no electron transfer occurs (such as those involving covalent bonds).

7 In the following redox reaction, hazardous sodium metal reacts with toxic chlorine gas to form the ionic compound sodium chloride, or common table salt:

8 Redox reactions Oxidation states can be useful for balancing chemical equations for oxidation-reduction (or redox) reactions, because the changes in the oxidized atoms have to be balanced by the changes in the reduced atoms. For example, in the reaction of acetaldehyde with the Tollens' reagent to acetic acid (shown below), the carbonyl carbon atom changes its oxidation state from +1 to +3

9 oxidation). This oxidation is balanced by reducing two equivalents of silver from Ag + to Ag 0.

10 Redox Sodium and fluorine bonding ionically to form sodium fluoride. Sodium loses its outer electron to give it a stable electron configuration, and this electron enters the fluorine atom exothermically. The oppositely charged ions are then attracted to each other. The sodium is oxidized, and the fluorine is reduced.

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12 Oxidizing and reducing agents In redox processes, the reductant transfers electrons to the oxidant. Thus, in the reaction, the reductant or reducing agent loses electrons and is oxidized, and the oxidant or oxidizing agent gains electrons and is reduced. The pair of an oxidizing and reducing agent that are involved in a particular reaction is called a redox pair A redox couple is a reducing species and its corresponding oxidized form, e.g., Fe 2+ /Fe 3+.

13 Metal displacement A redox reaction is the force behind an electrochemical cell like the Galvanic cell pictured. The battery is made out of a zinc electrode in a ZnSO 4 solution connected with a wire and a porous disk to a copper electrode in a CuSO 4 solution

14 # What is Oxidation # What is reduction. # Explain Oxidizing and reducing agents. #Describe Metal displacement.

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