17.1 Balancing Oxidation-Reduction Reactions

17.1 Balancing Oxidation-Reduction Reactions

• By the end of this section, you will be able to: lightning, static electricity, the current generated by a battery as it discharges, and many other influences are included in electricity.
• The electric current is the flow or movement of charge.

• The charge may be carried by electron or ion.
• The charge of a protons is equal to the charge of an electron.
• The SI unit of charge is the coulomb and the charge of a protons.

• The SI base unit for electrical current is the ampere, which is a flow rate of 1 coulomb of charge per second.
• It is necessary to keep a closed path in most chemical systems.
• There is an electrical potential difference between two points in the circuit that causes the flow of charge.
• The V is the SI unit of electrical potential.
• When a coulomb of charge moves through a potential difference, it gains or loses energy.
• Table 17.1 summarizes the information about electricity.

• Electricity-related phenomena include lightning, static electricity, and current produced by a battery.
• The OpenStax book is available for free at http://cnx.org/content/col11760/1.9 chemical equation was relatively simple.
• The half-reaction method is used for balancing oxidation-reduction reactions.
• The use of half-reactions is important for balancing more complicated reactions and it is also important because many aspects of electrochemistry are easier to discuss in terms of half-reactions.
• There are no good alternatives to half-reactions for discussing what is happening in many systems.

• acidic, basic, or neutral solutions are frequently used for chemical reactions.
• The nature of the solution may be important when balancing oxidation-reduction reactions.
• It helps to see the problem.

• Each half-reaction contains the same element in two different states.
• The iron lost an electron and underwent oxidation.
• The reduction is not obvious, but the manganese gained five electrons.

• It is possible to use hydrogen ion directly or as a reactant that reacts with oxygen to generate water.
• In acidic solutions where the reactants or products contain hydrogen and/or oxygen, hydrogen ion is very important.
• The oxidation half-reaction doesn't involve hydrogen or oxygen, so hydrogen ion isn't needed to balance.
• Oxygen is involved in the reduction half-reaction.
• Oxygen can be converted to water by using hydrogen ion.

• The basic solution has a lower hydrogen ion concentration and a higher hydroxide ion concentration.
• We will look at how basic solutions differ from acidic solutions after finishing this example.
• It is easier to treat a neutral solution as acidic than it is to treat it as basic.

• The iron atoms in the oxidation half-reaction are balanced, but the charges on the ion are not equal.
• To balance the charge, it is necessary to use electrons.

• The charge on an electron and the number of electrons are included in the charges.

• The half-reaction is balanced if the atoms and charges balance.
• electrons appear as products in oxidation half-reactions Since iron underwent oxidation, it is the reducing agent.

• It is necessary to check for charge balance because the atoms are balanced.
• There is a total charge on the left of the arrow and a total charge on the right.
• It is necessary to add five electrons to the left side of Chapter 17 to achieve charge balance.

• On the left side, electrons appear as reactants.

• There are two balanced half-reactions.

• The half-reactions can be combined with the electrons.
• The electrons are lost during oxidation.
• The electrons will cause a reduction.
• The reduction half-reaction must have the same number of electrons as the oxidation half-reaction.
• There is no excess or missing electrons.
• The oxidation half-reaction requires one electron while the reduction half-reaction requires five.
• The oxidation half-reaction by five and the reduction half-reaction by one are the lowest common multiples of one and five.

• This is the equation in the acidic solution.
• The most common error occurs during the multiplication of the individual half-reactions if something does not check.

• We wanted the solution to be basic.
• Basic solutions have excess hydroxide ion.
• The hydrogen ion will react with the hydroxide ion to produce water.
• The simplest way to generate the balanced equation in basic solution is to start with the balanced equation in acidic solution and convert it to the equation for basic solution.
• It is important to exercise caution when doing this, as many reactants behave differently under basic conditions and metal ion will form as the metal hydroxide.

• It is possible to balance any oxidation-reduction reaction with an acidic reaction and then convert the equation to a basic reaction.
• If the basic reactants and products are the same as the acidic ones, this will work.
• There are very few examples of basic and acidic reactions.
• It is possible to balance a basic reaction as acidic and then convert it to basic.
• To convert to a basic reaction, it is necessary to add the same number of hydroxide ion to each side of the equation.
• Water is produced by combining hydrogen ion with OH-.

• We can now try a basic equation.

• When necessary, simplifying should be done.
• It is necessary to remove one H2O from each side of the reaction arrows.

• This is the overall equation in the basic solution.

• An unbalanced oxidation half-reaction and an unbalanced reduction half-reaction are what this is.

• The four oxygen atoms in the permanganate need to be converted into four water molecule.

• The balanced equation is in acidic solution.

• It is necessary to convert the four O atoms in the MnO - 4 minus the two O atoms in the MnO2 into two water molecule.

• The balanced equation is in acidic solution.

• The basic solution has a balanced equation in it.

• In the type of solution indicated, balance the following.

• The oxidizing agents are identified by Fe2+ + Ag.