The critical volume provides data which may be tested for additive relations.
Other physical properties of these solutions, such as density, colour, optical rotatory power, &c., like the conductivities, are additive, i.e.
To Landolt is due the proof that, Additive reiations.
Kopp, begun in 1842, on the molecular volumes, the volume occupied by one gramme molecular weight of a substance, of liquids measured at their boiling-point under atmospheric pressure, brought to light a series of additive relations which, in the case of carbon compounds, render it possible to predict, in some measure, the cornposition of the substance.
The molecular volume is additive in certain cases, in particular of analogous compounds of simple constitution.
7V k / R, and since Vk is proportional to the volume at absolute zero, the ratio T k /P k should exhibit additive relations.
6 1.86 3.01 o 88 1.03 Since at the boiling-point under atmospheric pressure liquids are in corresponding states, the additive nature of the critical coefficient should also be presented by boiling-points.
It may he shown theoretically that the absolute boiling-point is proportional to the molecular volume, and, since this property is additive, the boiling-point should also be additive.
No additive constant being necessary if t be reckoned from the instant of starting, when 4=o.
While certain additive relations hold between some homologous series, yet differences occur which must be referred to the constitution of the molecule.
No Doubt There Must Be Approximate Relations Between The Atomic And Molecular Heats Of Similar Elements And Compounds, But Considering The Great Variations Of Specific Heat With Temperature And Physical State, In Alloys, Mixtures Or Solutions, And In Allotropic Or Other Modifications, It Would Be Idle To Expect That The Specific Heat Of A Compound Could Be Accurately Deduced By Any Simple Additive Process From That Of Its Constituents.
Schroeder the silver salts of the fatty acids exhibit additive relations; an increase in the molecule of CH2 causes an increase in the molecular volume of about 15'3.
Kopp systematized the earlier observations, and, having made many others, he was able to show that the molecular heat was an additive property, i.e.
They are characterized by their additive reactions: combining with water to form acids, with alcohols to form esters, and with primary amines to form amides.
Unsaturated aldehydes are also known, corresponding to the olefine alcohols; they show the characteristic properties of the saturated aldehydes and can form additive compounds in virtue of their unsaturated nature.
Walden (ibid.) has shown that certain salts dissolve in liquid sulphur dioxide forming additive compounds, two of which have been prepared in the case of potassium iodide: a yellow crystalline solid of composition, KI 14 S0 2, and a red solid of composition, KI 4S0 2.
The most direct manner in which to test any property for additive relations is to determine the property for a number of elements, and then investigate whether these values hold for the elements in combination.
An important distinction separates true mixed crystals and crystallized double salts, for in the latter the properties are not linear functions of the properties of the components; generally there is a contraction in /10.591 volume, while the re fractive indices and other physical properties do not, in general, obey the additive law.
The omission of the additive arbitrary constants of integration in (8) is equivalent to a special choice of the origin 0 of co-ordinates; viz.
This is shown in the following table (the values are for Ha) Additive relations undoubtedly exist, but many discrepancies occur which may be assigned, as in the case of molecular volumes, to differences in constitution.