redox
A reversible chemical reaction in which one reaction is an oxidation and the reverse is a reduction.
Examples of redox in the following topics:

Redox Titrations
 Redox titration determines the concentration of an analyte containing either an oxidizing or a reducing agent.
 A student conducts the redox titration and reaches the endpoint after adding 25 mL of the titrant.
 There are various other types of redox titrations that can be very useful.
 A redox titration using potassium permanganate as the titrant.
 Calculate the concentration of an unknown analyte by performing a redox titration.

Types of Redox Reactions
 Redox reactions are all around us.
 In fact, much of our technology, from fire to laptop batteries, is largely based on redox reactions.
 Redox (reductionoxidation) reactions are those in which the oxidation states of the reactants change.
 In some redox reactions, substances can be both oxidized and reduced.
 This is an example of a combustion reaction, a redox process.

Balancing Redox Equations
 For example, look at the following redox reaction between iron and copper:
 If a reaction occurs in an acidic environment, you can balance the redox equation as follows:
 The following is an unbalanced redox equation that takes place in acidic solution:
 A great walkthrough on how to balance a redox reaction in basic solution.
 A great walkthrough on how to balance a redox reaction in acidic solution.

Thermodynamics of Redox Reactions
 The thermodynamics of redox reactions can be determined using their standard reduction potentials and the Nernst equation.
 In order to calculate thermodynamic quantities like change in Gibbs free energy $\Delta G$ for a general redox reaction, an equation called the Nernst equation must be used.
 Translate between the equilibrium constant/reaction quotient, the standard reduction potential, and the Gibbs free energy change for a given redox reaction

Predicting Spontaneous Direction of a Redox Reaction
 The direction of a redox reaction depends on the relative strengths of the oxidants and reductants in a solution.
 Generally, the direction of a redox reaction depends on the relative strengths of oxidants and reductants in a solution.
 In order to predict if two reactants will take part in a spontaneous redox reaction, it is important to know how they rank in an electrochemical series.
 Predict the direction of electron flow in a redox reaction given the reduction potentials of the two halfreactions

Balancing Redox Equations
 Balancing redox reactions depends on conservation of mass and electrons; the exact method varies with basic or acidic solutions.
 Redox (oxidationreduction) reactions include all chemical reactions in which atoms have their oxidation states changed.
 An alternative method for balancing reduction/oxidation (redox) reactions.
 It consists of four steps that, if followed, can balance any redox equation.
 Produce a balanced redox equation from an unbalanced one in either acidic or basic media

Free Energy and Cell Potential
 In a galvanic cell, where a spontaneous redox reaction drives the cell to produce an electric potential, the change in Gibbs free energy must be negative.
 In a galvanic cell, where a spontaneous redox reaction drives the cell to produce an electric potential, the change in Gibbs free energy must be negative.
 Calculate the change in Gibbs free energy of an electrochemical cell where the following redox reaction is taking place:
 Because the change in Gibbs free energy is negative, the redox process is spontaneous.
 Calculate the change in Gibbs free energy of an electrochemical cell, and discuss its implications for whether a redox reaction will be spontaneous

Oxidation of Phenols
 The redox equilibria between the dihydroxybenzenes hydroquinone and catechol and their quinone oxidation states are so facile that milder oxidants than chromate (Jones reagent) are generally preferred.
 The position of the quinonehydroquinone redox equilibrium is proportional to the square of the hydrogen ion concentration, as shown by the following halfreactions (electrons are colored blue).

Voltaic Cells
 A voltaic cell is a device that produces an electric current from energy released by a spontaneous redox reaction in two halfcells.
 An electrochemical cell is a device that produces an electric current from energy released by a spontaneous redox reaction.
 The operating principle of the voltaic cell is a simultaneous oxidation and reduction reaction, called a redox reaction.
 This redox reaction consists of two halfreactions.
 In a typical voltaic cell, the redox pair is copper and zinc, represented in the following halfcell reactions:

Standard Reduction Potentials
 Reduction potential (also known as redox potential, oxidation/reduction potential, or Eh) measures the tendency of a chemical species to acquire electrons and thereby be reduced.
 However, because these can also be referred to as "redox potentials," the terms "reduction potentials" and "oxidation potentials" are preferred by the IUPAC.