Equilibrium condition for Kelvin’s Vapor Pressure-curvature equation

Asked by: Crystal White

What does the Kelvin equation tell us about?

The Kelvin equation¹ relates the equilibrium vapour pressure of a liquid to the curvature of the liquid–vapour interface. It predicts that undersaturated vapours will condense in channels of sufficiently small dimensions.
16 апр. 1981

What is Kelvin equation in surface chemistry?

The Kelvin equation describes the change in vapour pressure due to a curved liquid–vapor interface, such as the surface of a droplet. The vapor pressure at a convex curved surface is higher than that at a flat surface.

Why does a curved interface cause the vapor pressure of substance change?

If the surface is curved, then the amount of bonding that can go on between any one water molecule on the surface and its neighbors is reduced. As a result, there is a greater probability that any one water molecule can escape from the liquid and enter the vapor phase. Thus, the evaporation rate increases.

What is K vapor pressure?

Ki is called the vapor–liquid equilibrium ratio, or simply the K-value, and represents the ratio of the mole fraction in the vapor, yi, to the mole fraction in the liquid, xi. Equation (2) is also called “Henry’s law” and K is referred to as Henry’s constant.

What are Kelvin relationships?

Kelvin’s relations may be considered as cornerstones in the theory of thermoelectricity. Indeed, they gather together the three thermoelectric effects, associated respectively with Seebeck, Peltier and Thomson, to get a unique and consistent description of thermoelectric phenomena.

What is surface tension discuss Laplace equation?

In physics, the Young–Laplace equation (/ləˈplɑːs/) is an algebraic equation that describes the capillary pressure difference sustained across the interface between two static fluids, such as water and air, due to the phenomenon of surface tension or wall tension, although use of the latter is only applicable if

What is a Kelvin in temperature?

The kelvin (abbreviation K), less commonly called the degree Kelvin (symbol, ^o K), is the Standard International ( SI ) unit of thermodynamic temperature. One kelvin is formally defined as 1/273.16 (3.6609 x 10 ^–3 ) of the thermodynamic temperature of the triple point of pure water (H ₂ O).

What is Kelvin radius?

Kelvin equation describes the change of vapour pressure over liquid curved with a radius r (for example, in a capillary or over a droplet). The Kelvin equation is used for determination of pore size distribution of a porous medium using adsorption porosimetry. Where: p – actual vapour pressure.

What is Gibbs adsorption isotherm?

The Gibbs Adsorption Isotherm equation is a two-dimensional analogous of the Gibbs-Duhem equation, and it is one of the cornerstones of interface science. It is also widely used to estimate the surface excess concentration (SEC) for surfactants and other compounds in aqueous solution, from surface tension measurements.

How do you calculate equilibrium vapor pressure?

In chemistry, vapor pressure is the pressure that is exerted on the walls of a sealed container when a substance in it evaporates (converts to a gas). To find the vapor pressure at a given temperature, use the Clausius-Clapeyron equation: ln(P1/P2) = (ΔH_vap/R)((1/T2) – (1/T1)).

How do you find the equilibrium vapor pressure of a liquid?

The vapor pressure of the liquid can be measured using the manometer. It is done by injecting a small amount of liquid in a closed flask that is connected to a manometer.

What is vapour pressure curve?

A vapor pressure curve is a graph of vapor pressure as a function of temperature. To find the normal boiling point of liquid, a horizontal line is drawn from the y-axis at a pressure equal to standard pressure.

Why is the Kelvin scale often used in scientific calculations?

The Kelvin temperature scale is used by scientists because they wanted a temperature scale where zero reflects the complete absence of thermal energy. As you get to lower and lower temperatures, there are less and less vibrations in the material to provide these thermal excitations.

Why do we have to use Kelvin for gas laws?

The Kelvin scale is used in gas law problems because the pressure and volume of a gas depend on the kinetic energy or motion of the particles. The Kelvin scale is proportional to the KE of the particles… that is, 0 K (absolute zero) means 0 kinetic energy.

What do you understand by equilibrium temperature?

Scientific definitions for thermal equilibrium



The condition under which two substances in physical contact with each other exchange no heat energy. Two substances in thermal equilibrium are said to be at the same temperature.

What is a Kelvin in temperature?

The kelvin (abbreviation K), less commonly called the degree Kelvin (symbol, ^o K), is the Standard International ( SI ) unit of thermodynamic temperature. One kelvin is formally defined as 1/273.16 (3.6609 x 10 ^–3 ) of the thermodynamic temperature of the triple point of pure water (H ₂ O).

What is Kelvin radius?

Kelvin equation describes the change of vapour pressure over liquid curved with a radius r (for example, in a capillary or over a droplet). The Kelvin equation is used for determination of pore size distribution of a porous medium using adsorption porosimetry. Where: p – actual vapour pressure.

Why does capillary condensation occur?

Capillary condensation occurs when vapor condensation is below the saturation vapor pressure of the pure liquid fraction of the same substance. This is described by an increase in van der Waals interactions between vapor phase molecules inside a confined space (a capillary, pocket or vapor space).

What is a symbol of chemical potential?

The standard chemical potential, \(\mu\st\), of a pure substance in a given phase and at a given temperature is the chemical potential of the substance when it is in the standard state of the phase at this temperature and the standard pressure \(p\st\).

What is the phase equilibrium ratio?

Explanation: Phase equilibrium ratio is the ratio of mole fractions of species in two phases at equilibrium.

Is chemical potential same as equilibrium?

At chemical equilibrium or in phase equilibrium, the total sum of the product of chemical potentials and stoichiometric coefficients is zero, as the free energy is at a minimum. In a system in diffusion equilibrium, the chemical potential of any chemical species is uniformly the same everywhere throughout the system.