If you are using proper browser, you can calculate properties with JOBACK method. This program calculate, boiling point, Critical temperature. Property Estimation Joback Method spreadsheet calculates thermophysical and transport properties as a function of the sum of group parameters. Some of the. The Joback method is a group contribution method. These kind of methods use basic structural information of a chemical molecule like a list of simple functional .

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The normal boiling point is estimated by Joback’s method [1], a group contribution technique. For many purposes it is convenient to report heat capacity as an intensive property. A term and a polynomial with no indeterminates are called, respectively, a constant term, the degree of a constant term and of a nonzero constant polynomial is 0. Quantum theory can be used to predict the heat capacity of simple systems.

Please your comments and suggestions. Estimates generated by the Racket equation have an average absolute percent error of 5. The longest series of linked carbon atoms in a molecule is known as its skeleton or carbon backbone.

However, the liquid-vapor boundary terminates in an endpoint at some critical temperature Tc, in water, the critical point occurs at around K and Carbon dioxide exuding fog while cooling from supercritical to critical temperature. The word viscosity is derived from the Latin viscum, meaning mistletoe, the dynamic viscosity of a fluid expresses its resistance to shearing flows, where adjacent layers move parallel to each other with different speeds.


The critical volume is estimated by Joback’s method [1], a group contribution technique. The best coverage has been achieved for normal boiling points components and the worst for heat of fusion components. The DDB has since extended to many other properties and has increased dramatically in size also because of intensive government aid. Joback extended the range of supported properties, created new parameters and modified slightly the formulas of the old Lydersen method.

In advanced mathematics, polynomials are used to construct polynomial rings and algebraic varieties, central concepts in algebra, the word polynomial joins two diverse roots, the Greek poly, meaning many, and the Latin nomen, or name. If both alkyl groups in a ketone are the same then the ketone is said to be symmetrical, although used infrequently, oxo is the IUPAC nomenclature for a ketone functional group. The Haller-Bauer reaction occurs between a non-enolizable ketone and a strong amide base.

The best coverage has been achieved for normal boiling points components and the worst for heat of fusion components. Other group contribution methods, especially methods like UNIFACwhich estimate mixture properties like activity coefficients, use both simple additive group parameters and group interaction parameters.

How to use Joback Properties estimation method, HTML5 program

An external force is required in order to keep the top plate moving at constant speed. In this prototypical example involving benzophenone, the tetrahedral intermediate expels phenyl anion to give benzamide and benzene as the organic products.

Liquids with higher viscosities make smaller splashes when poured at the same velocity. The molecular weight is estimated by its definition – the molecular weight is the sum of the atomic weight of each atom in the molecule.


See this report for a more detailed evaluation of the technique. When the two groups are the same, the prefix di- is added before the name of jobaci group. It is a convention to use uppercase letters for the indeterminates.

Joback method

This doesn’t describe the real behavior of the normal boiling points correctly. To estimate properties for 1-butanol you would:. A sample containing twice the amount of substance as another sample requires the transfer of twice the amount of heat to achieve the change in temperature. Certain methyl groups can be deprotonated, for moback, the acidity of the methyl groups in acetone is about more acidic than methane. Languages Deutsch Edit links.

Joback method – WikiVisually

If a group is present multiple metho each occurrence is counted separately. This technique is an equation oriented technique that requires the molecular weight, the critical compressibility, the critical temperature and the critical pressure.

The list of groups don’t cover many common molecules sufficiently. Volume 57, page One group of the alkanes are waxes, solids at standard ambient temperature and pressure.