Aplications of the oxidation-reduction process

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Chapter 3 - Biological Psychology LECTURE 3

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Aplications of the oxidation-reduction process

Applications of electrochemical reactions

Industry

Molten NaCl electrolysis: method widely used in industry to obtain sodium and chlorine in its elemental state

Mettalic coatings, electroplating: applying a thin layer of metal on an electronic current conducting surface

Electric batteries: They are the industrialized and commercial formats of galvanic cells. (car batteries are the traditional battery model)

Nature

Corrosion in metals

Electric eels

Nerve impulses generated neurons

Electrolytic cells

To force a chemical reaction that would otherwise not occur

Electrochemical cell in which electrical energy is used to drive a non-spontaneous oxidation-reduction reaction

Galvanic or voltaic cells

Function

To supply electrical current through a redox reaction to the transfer of electrons

Definition

Devices capable of generating an electric current from a spontaneous chemical reaction of oxidation-reduction

Steps to balance a redox reaction

Check that both sides of the equation have the same number of atoms of each element

Balance the remaining elements that do not oxidize or reduce to obtain the balanced equation

Transfer the coefficient that appears in front of each substance in the half-balanced reactions

Match the number of electrons lost in oxidation to the number of electrons gained in reduction

Balance the charge in each equation. This should be done after the balance of mass.

Perform the balance of mass. Same number of chemical species on both sides

Write the two oxidation and reduction half-reactions

Identify the elements that change their oxidation state or charge

Assign the oxidation numbers to each element in the reaction

Oxidation number

Are the assigned charges to the different atoms involved of a species

Oxidizing and reducing agents

Reducing agent

Increases its oxidation number

Loses electrons

Oxidizing agent

Decreases its oxidation number

Gain electrons

Oxidation and reduction concepts

Reduction: electron gain

Oxidation: loss of electrons

Whenever one species is reduced, there is another that is oxidized