The half-reactions that occur in ordinary alkaline batteries can be written as In 1999, researchers in Israel reported a new type of alkaline battery, called a 'super-iron' battery. This battery uses the same anode reaction as an ordinary alkaline battery but involves the reduction of FeO₄^2- ion (from K₂FeO₄) to solid Fe(OH)₃ at the cathode. (a) Use the following standard reduction potential and any data from Appendixes C and D to calculate the standard cell potential expected for an ordinary alkaline battery:

Key Concepts

Standard Reduction Potential

Standard reduction potential is a measure of the tendency of a chemical species to gain electrons and be reduced. It is measured in volts and is determined under standard conditions (1 M concentration, 1 atm pressure, and 25°C). Each half-reaction has a specific standard reduction potential, which can be used to predict the direction of electron flow in electrochemical cells.

Electrochemical Cell

An electrochemical cell consists of two electrodes (anode and cathode) where oxidation and reduction reactions occur, respectively. The anode is where oxidation takes place, releasing electrons, while the cathode is where reduction occurs, accepting electrons. The overall cell potential is calculated by subtracting the anode potential from the cathode potential, indicating the cell's ability to do electrical work.

Nernst Equation

The Nernst equation relates the cell potential to the concentrations of the reactants and products involved in the electrochemical reaction. It allows for the calculation of the cell potential under non-standard conditions, taking into account temperature and concentration changes. This equation is crucial for understanding how the potential of a battery can vary in practical applications.