Electrochemistry Conductance Quiz

The conductivity of an electrolyte solution is influenced by the size of the ions present. Larger ions exhibit lower conductivity due to increased solvation and decreased mobility.

Solvents with higher viscosity (thickness) impede the movement of ions, resulting in lower conductivity.

The dielectric constant of a solvent reflects its ability to weaken the attractive forces between ions. Higher dielectric constants lead to greater ionization and increased conductivity.

The force of attraction between two charged particles is directly proportional to the product of their charges and inversely proportional to the square of the distance between them.

Specific conductivity (κ) of a solution is directly proportional to the number of ions present. It's a measure of the solution's ability to conduct electricity.

Specific conductivity increases with increasing electrolyte concentration up to a certain point. However, equivalent conductivity decreases due to increasing interionic interactions.

Equivalent conductance (Λ) measures the conductivity of one equivalent of an electrolyte. It decreases with increasing concentration due to increased interionic attractions.

The potential difference between the charged surface of a metal electrode and the oppositely charged ionic layer in solution.

The formation of an EDL depends on the relative chemical potentials of the metal ions in the solid state (µim) and in solution (µis).

When the chemical potential of the metal ions in the solid state is higher than in solution (µim > µis), the metal oxidizes and dissolves, leaving the surface with excess negative charges.

When the chemical potential of the metal ions in solution is higher than in the solid state (µis > µim), ions from the solution reduce onto the metal surface, leaving the metal with excess positive charges.

When the chemical potentials of the metal ions in solid and solution are equal (µis = µim), no ionic transfer occurs, and the surface charge is zero. There is no EDL formed.

The position of a metal in the electrochemical series determines whether it will oxidize or reduce in a given electrolyte.

An external potential applied to a metal electrode in contact with an electrolyte can create an EDL.

Specific adsorption of ions onto a metal surface due to binding forces (covalent or Van der Waals) can lead to EDL formation.

The formation of an EDL can be accompanied by changes in the concentration of the electrolyte solution near the electrode surface.

The Helmholtz-Perrin model suggests that the electrical double layer at an electrode-electrolyte interface is a simple, fixed structure, but experimental observations contradict this.

The Gouy-Chapman model proposes a diffuse double layer, where ions are distributed in a cloud-like manner due to their thermal energy and electrostatic interactions with the electrode.

Electrostatic interactions between ions and the electrode, as well as their thermal motion, affect the distribution of ions near the electrode surface.

The model predicts that the capacitance of the electrical double layer is not constant but changes with potential, which aligns with experimental observations.

The Gouy-Chapman model explains the dependence of surface tension and capacitance on the concentration of the electrolyte solution.

The Gouy-Chapman model predicts that the charge on a colloidal particle is not always completely balanced by the counter-ions in its surrounding solution.

The diffuse nature of the double layer allows for a more realistic description of the interface and its behavior.

The Gouy-Chapman model provides a more accurate representation of the electrical double layer by taking into account the diffuse nature of the ion distribution.

The Gouy-Chapman model clarifies the behavior of the electrical double layer, which is essential for understanding processes like electrolysis and electrokinetic phenomena.

The Gouy-Chapman model predicts that the capacitance of the electrical double layer decreases with increasing electrolyte concentration due to the compression of the diffuse ion cloud.

The minimum potential required to initiate electrolysis in an electrochemical cell.

The current observed before the decomposition potential is reached, often attributed to charging the electrical double layer and reducing impurities.

The current that is reached after the decomposition potential, where the rate of mass transfer is high, and the process is controlled by activation.

The difference between the applied potential and the reversible decomposition potential, representing the extra energy required to overcome resistance and initiate electrolysis.

The potential difference required to maintain a certain decomposition current in an electrolytic cell, taking into account the reversible electrode potential, activation overpotentials, and ohmic resistance.

The potential difference across an electrified interface (like a metal electrode in solution) can be divided into two parts: the potential drop across the Helmholtz layer (a rigid layer of ions adhering to the electrode surface) and the potential drop across the diffuse layer (a region further away from the electrode where ions are more mobile).

The Helmholtz layer refers to a thin, rigid layer of ions that strongly adhere to the surface of an electrode in an electrolyte solution. This layer represents the first layer of charge accumulation at the interface.

The diffuse layer refers to the region in an electrolyte solution extending outward from the Helmholtz layer. In this region, ions are more mobile and influenced by both electrostatic attraction and thermal forces, creating a more dispersed charge distribution.

The potential difference across the Helmholtz layer is denoted as (ψM - ψH), where ψM is the potential at the metal surface, and ψH is the potential at the Helmholtz plane.

The potential difference across the diffuse layer is denoted as (ψH - ψB), where ψH is the potential at the Helmholtz plane, and ψB is the potential in the bulk solution.

The total potential drop across the electrified interface is given by (ψM - ψB), which is the sum of the potential drops across the Helmholtz layer and the diffuse layer.

The capacity of an interface refers to its ability to store charge. It is defined as the change in charge (dq) divided by the change in potential (dψ).

The total capacity of the interface (ct) is determined by the Helmholtz capacity (cH) and the Gouy-Chapman capacity (cG).

The Helmholtz-Perrin capacity (cH) measures the ability of the Helmholtz layer to store charge. This capacity is related to the potential drop across the layer.

The Gouy-Chapman capacity (cG) measures the ability of the diffuse layer to store charge. This capacity is related to the potential drop across the diffuse layer.