An electrochemical cell consists of a nickel metal electrode...

An electrochemical cell consists of a nickel metal electrode immersed in a solution with $\left[\mathrm{Ni}^{2+}\right]=1.0 M$ separated by a porous disk from an aluminum metal electrode. a. What is the potential of this cell at $25^{\circ} \mathrm{C}$ if the aluminum electrode is placed in a solution in which $\left[\mathrm{Al}^{3+}\right]=7.2 \times 10^{-3} M ?$ b. When the aluminum electrode is placed in a certain solution in which $\left[\mathrm{Al}^{3+}\right]$ is unknown, the measured cell potential at $25^{\circ} \mathrm{C}$ is $1.62 \mathrm{~V} .$ Calculate $\left[\mathrm{Al}^{3+}\right]$ in the unknown solution. (Assume Al is oxidized.)

An electrochemical cell consists of a nickel metal electrode immersed in a solution with $\left[\mathrm{Ni}^{2+}\right]=1.0 M$ separated by a porous disk from an aluminum metal electrode.
a. What is the potential of this cell at $25^{\circ} \mathrm{C}$ if the aluminum electrode is placed in a solution in which $\left[\mathrm{Al}^{3+}\right]=7.2 \times 10^{-3} M ?$
b. When the aluminum electrode is placed in a certain solution in which $\left[\mathrm{Al}^{3+}\right]$ is unknown, the measured cell potential at $25^{\circ} \mathrm{C}$ is $1.62 \mathrm{~V} .$ Calculate $\left[\mathrm{Al}^{3+}\right]$ in the unknown solution. (Assume Al is oxidized.)

Key Concepts

The Nernst Equation

The Nernst equation is fundamental for calculating the cell potential under non-standard conditions, relating the electrode potential to the standard electrode potential, temperature, number of electrons transferred, and the reaction quotient. It shows how variation in ion concentrations influences the cell potential.

Reaction Quotient and Concentration Effects

The reaction quotient (Q) in the Nernst equation quantifies the relative activities (or concentrations) of the reactants and products at any given moment. It helps determine the direction of the reaction and the deviation of the cell potential from its standard value based on the current concentrations of the ions in the half-cells.

Half-Reactions and Redox Processes

In redox chemistry, reactions are split into two half-reactions: one for oxidation (loss of electrons) and one for reduction (gain of electrons). Properly balancing these half-reactions, including electron transfer, is critical for determining the overall cell reaction and for calculating the cell potential.

Standard Electrode Potentials

Standard electrode potentials represent the inherent tendency of a chemical species to gain or lose electrons under standard conditions (1 M concentration, 25°C, 1 atm pressure). They serve as reference values in determining the feasibility and direction of redox reactions when paired with other half-reactions in a cell.

Electrochemical Cells

Electrochemical cells are systems where chemical reactions generate electrical energy by separating oxidation and reduction reactions into different compartments. They consist of two electrodes immersed in solutions containing relevant ions, with a salt bridge or porous partition that permits ion transfer to maintain charge balance while allowing electron flow through an external circuit.

Transcript

Please give Ace some feedback