Electrochemistry Concepts

The branch of chemistry that studies the relationship between chemical and electrical energy, and how they are converted into each other in redox reactions.

A device that converts chemical energy into electrical energy through a spontaneous redox reaction.

A device that uses electrical energy to drive a non-spontaneous redox reaction.

The ability of a solution to conduct electricity. It's a measure of how easily electrical current flows through the solution.

The measure of the conductivity of a solution that contains 1 mole of dissolved electrolyte.

A law stating that the limiting molar conductivity of an electrolyte is the sum of the limiting molar conductivities of its individual ions, multiplied by their respective number.

The ratio of the molar conductivity of an electrolyte at a specific concentration to its limiting molar conductivity.

The molar conductivity of an electrolyte at infinite dilution. This is the theoretical conductivity of the electrolyte when it is completely dissociated.

The amount of electrical charge required to oxidize one mole of a substance.

The constant value that relates the conductivity of a solution to the cell constant.

The electrochemical cell that converts chemical energy into electrical energy through a spontaneous redox reaction.

The reaction that occurs at the cathode in a fuel cell.

The reaction that occurs at the anode in a fuel cell.

The amount of electrical work done in a Galvanic cell is equal to the change in free energy of the system.

A lead storage battery is classified as both an electrolytic cell during charging and a Galvanic cell during discharging.

In a Galvanic cell, the flow of conventional current is from the anode (where oxidation occurs) to the cathode (where reduction occurs).

Mercury (Hg) is the only metal that doesn't react with water to form an oxide or hydroxide and release hydrogen gas.

Electrolysis of an aqueous solution of CuSO4 leads to a decrease in pH because the electrolysis process consumes OH- ions, making the solution more acidic.

Zinc cannot displace sodium ions from their aqueous solutions because sodium is more reactive than zinc.

The conductivity of a solution decreases with increasing concentration because ion-ion interactions become more significant, hindering their mobility.

A primary battery, like the Leclanche cell, cannot be recharged. It provides a constant voltage throughout its lifetime but can only be used once.

The resistance of the solution between the electrodes of a conductivity cell, measured in ohms (Ω).

The product of the cell constant and the resistance of the solution. It measures the conductivity of the solution.

The product of the conductivity and the resistance of the cell. It is a measure of the cell constant, which is the distance between the electrodes divided by the area of the electrodes.

The process of using electrical energy to drive a non-spontaneous chemical reaction.

The potential difference between two electrodes of an electrochemical cell at standard conditions.

The relationship between change in Gibbs free energy (ΔG°) and standard cell potential (E°).

A measure of the equilibrium constant for a reaction, calculated using the standard cell potential and the Faraday constant.

Electrolytes that completely dissociate into ions in solution. They have high conductivity even at low concentrations.

Electrolytes that only partially dissociate into ions in solution. The conductivity of weak electrolytes is much lower because they don't have as many free ions in solution.

The strength of an oxidizing agent is its ability to gain electrons. A stronger oxidizing agent has a greater tendency to gain electrons and get reduced.

The stronger the oxidizing agent, the more positive the standard reduction potential (E°). A more positive E° indicates a greater tendency for reduction, meaning gaining electrons.

The order of increasing strength for oxidizing agents is Cl2 < MnO4- < Ce4+, meaning Ce4+ is the strongest oxidizing agent, followed by MnO4-, and then Cl2.

The conductivity of a solution measures its ability to conduct electricity. A higher conductivity indicates a greater ability to conduct electricity.

Molar conductivity is the conductivity of a solution containing 1 mole of the dissolved electrolyte. It's a measure of how well a solution conducts electricity per mole of electrolyte.

For strong electrolytes, molar conductivity decreases slightly with increasing concentration. This is because the ions are already fully dissociated, so increasing concentration doesn't significantly affect conductivity.

For weak electrolytes, molar conductivity increases significantly with decreasing concentration. As the concentration decreases, the degree of dissociation increases, leading to more ions and greater conductivity.

The graph shows the relationship between molar conductivity (Λm) and concentration (C) for strong and weak electrolytes. For strong electrolytes, the graph is a flat line, indicating minimal change in conductivity, while for weak electrolytes, the graph shows a steep increase in conductivity as concentration decreases.