Balancing Redox Reactions under Acidic Conditions

Follow the seven steps for balancing a redox reaction equation under acidic conditions ... 

Here s a summary of the method for balancing a redox reaction equation for a reaction under acidic conditions (excess H+) (see the next section for details on balancing a reaction under basic conditions) ... 

Calculating The concentration of thallium(I) ions in solution may be determined by oxidizing to thallium(III) ions with an aqueous solution of potassium permanganate (KMn04) under acidic conditions. Suppose that a 100.00 mL sample of a solution of unknown T1+ concentration is titrated to the endpoint with 28.23 mL of a 0.0560M solution of potassium permanganate. What is the concentration of T1+ ions in the sample You must first balance the redox equation for the reaction to determine its stoichiometry. 

You have seen many balanced chemical equations and net ionic equations that represent redox reactions. There are specific techniques for balancing these equations. These techniques are especially useful for reactions that take place under acidic or basic conditions, such as the acidic conditions used in coating a master CD with silver. 

Redox reactions do not always take place under neutral conditions. Balancing half-reactions is more complicated for reactions that take place in acidic or basic solutions. When an acid or base is present, or OH ions must also be considered. However, the overall approach is similar. This approach involves writing the correct formulas for the reactants and products, balancing the atoms, and adding the appropriate number of electrons to one side of the half-reaction to balance the charges. 

Self-redox. The reaction of NOg in water (see Problem 17) may also yield a mixture of nitric acid and nitric oxide under some conditions. Write die partial ionic equations and the balanced overall equation for the reaction that gives these products. 

---