J = diffusion flux - the amount of substance that flows through an unit area per unit time [mass or mol /(m 2 s)]
D = diffusion coefficient [m 2 /s]
dφ = change in concentration of substance [mass or mol/m 3 ]
dx = change in length [m]
For simple one-dimensional transport, the diffusion coefficient describes the time–rate of change of concentration . The diffusion coefficient varies from substance to substance and with temperature.
See Water and Heavy Water - thermodynamic properties.
See also Water Boiling points at high pressure , Boiling points at vacuum pressure , Density, specific weight and thermal expansion coefficient , Dynamic and kinematic viscosity , Enthalpy and entropy , Heat of vaporization , Ionization Constant, pK w , of normal and heavy water , Melting points at high pressure , Saturation pressure , Specific gravity , Specific heat (heat capacity) and Specific volume for online calculatores, and similar figures and tables as shown below, as well as Air - Diffusion Coefficients of Gases in Excess of Air
Diffusion coefficients for some common gases in water:
(Gas–liquid diffusion coefficients are difficult to measure, and since the values below are from different sources and different measuring methods, there is some uncertainty about the values)
|Gas in water|| Diffusion coefficient, D, [x10 -5 cm 2 /s ] |
at atmospheric pressure and given temperatures
|10 °C||15 °C||20 °C||25 °C||30 °C||35 °C|
|Name||Formula||50 °F||59 °F||68 °F||77 °F||86 °F||95 °F|
Material properties of gases, fluids and solids - densities, specific heats, viscosities and more.
Steam & condensate systems- properties, capacities, pipe sizing, systems configuration and more.
Thermodynamics of steam and condensate systems.
Work, heat and energy systems.
Hot and cold water service systems - design properties, capacities, sizing and more.
Diffusion coefficients (D12) for gases in large excess of air at temperatures ranging 0 - 400 °C.
Figures and tables withdry air thermal diffusivity vs. temperarure and pressure. SI and Imperial units.
Ammonia and health symptoms - smell and threat to life.
Figures and table with changes in Prandtl number for carbon dioxide with changes in temperature and pressure.
Chemical, physical and thermal properties of carbon dioxide. Phase diagram included.
Carbon dioxide concentration in a room may indicate air quality and ventilation system efficiency.
Flame and explosion limits for gases like propane, methane, butane, acetylene and more.
Thermodynamic properties of heavy water (D2O) like density, melting temperature, boiling temperature, latent heat of fusion, latent heat of evaporation, critical temperature and more.
Online calculator, figures and tables with melting points of ice to water at pressures ranging from 0 to 29000 psia (0 to 2000 bara). Temperature given as °C, °F, K and °R.
Moisture will flow through a building wall or roof if the vapor partial pressure is higher on one of the sides.
Solubility of oxygen in equilibration with air in fresh water and seawater (salt water) - pressures ranging 1 - 4 bar abs.
ppm - or parts per million - is commonly used as a unit of concentration.
Concentration of a pollution in a limited space as a room depends on the amount of polluted material spread in the room, supply of fresh air, outlets positions and construction, principles used for supply and outlet from the space.
Salinity - salt content - of fresh, brackish and sea water.
Solubility of Ammonia, Argon, Carbon Dioxide, Carbon Monoxide, Chlorine, Ethane, Ethylene, Helium, Hydrogen, Hydrogen Sulfide, Methane, Nitrogen, Oxygen and Sulfur Dioxide in water.
Online calculator, figures and tables showing boiling points of water at pressures ranging from 14.7 to 3200 psia (1 to 220 bara). Temperature given as °C, °F, K and °R.
Online calculator, figures and tables giving the boiling temperatures of water in varying vacuum, SI and Imperial units.
Definitions, online calculator and figures and tables with water properties like density, specific weight and thermal expansion coefficient of liquid water at temperatures ranging 0 to 360°C (32 to 680°F).
Free online calculator - figures and tables with viscosity of water at temperatures ranging 0 to 360°C (32 to 675°F) - Imperial and SI Units.
Figures and tables showing the enthalpy and entropy of liquid water as function of temperature - SI and Imperial Units.
Online calculator, figures and tables showing heat of vaporization of water, at temperatures from 0 - 370 °C (32 - 700 °F) - SI and Imperial units.
Ionization constant (= dissociation constant = self-ionization constant = ion product = autoprotolysis constant ) of water and heavy water, given as function of temperature (°C and °F) in figures and tables.
Figures and tables showing how the properties of water changes along the boiling/condensation curve (vapor pressure, density, viscosity, thermal conductivity, specific heat, Prandtl number, thermal diffusivity, entropy and enthalpy).
Online calculator, figures and tables with water saturation (vapor) pressure at temperatures ranging 0 to 370 °C (32 to 700°F) - in Imperial and SI Units.
Figures and tables showing specific gravity of liquid water in the range of 32 to 700 °F or 0 to 370°C, using water density at four different temperatures as reference.
Online calculator, figures and tables showing specific heat of liquid water at constant volume or constant pressure at temperatures from 0 to 360 °C (32-700 °F) - SI and Imperial units.
Online calculator, figures and tables showing Specific Volume of water at temperatures ranging from 0-370 °C and 32 - 700 °F - Imperial and IS Units.
Thermal properties of water at different temperatures like density, freezing temperature, boiling temperature, latent heat of melting, latent heat of evaporation, critical temperature and more.
Critical point is where vapor and liquid are indistinguishable and triple point is where ice, water and vapor coexist in thermodynamic equilibrium.
Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp from the Sketchup Extension Warehouse!
We don't collect information from our users. Only emails and answers are saved in our archive. Cookies are only used in the browser to improve user experience.
Some of our calculators and applications let you save application data to your local computer. These applications will - due to browser restrictions - send data between your browser and our server. We don't save this data.