The theoretical value for the depression of the freezing point of a dilute solution per gramme-equivalent of solute per litre is 1857° C. Completely ionized solutions of salts with two ions should give double this number or 3.714°, while electrolytes with three ions should have a value of 5.57°.
As the concentration is increased and un-ionized molecules are formed, a change in temperature begins to affect the ionization as well as the fluidity.
In the case of nonelectrolytes and of all non-ionized molecules this analogy completely represents the facts, and the phenomena of diffusion can be deduced from it alone.
They are ionized in aqueous solution to a much greater extent than ammonia, the quaternary ammonium bases being the most ionized, and the secondary bases being more strongly ionized than the primary or tertiary bases.
It is apparent that metallic salts of organic acids would, in aqueous solution, be ionized, the positive ion being the metal, and the negative ion the acid residue.
The constitution of the diazonium groupN 2 -X, may be inferred from the following facts :-The group C6H6N2-behaves in many respects similarly to an alkali metal, and even more so to the ammonium group, since it is capable of forming colourless neutral salts with mineral acids, which in dilute aqueous solution are strongly ionized, but do not show any trace of hydrolytic dissociation (A.
On mixing dilute solutions of the diazonium hydroxide and the alkali together, it is found that the molecular conductivity of the mixture is much less than the sum of the two electrical conductivities of the solutions separately, from which it follows that a portion of the ions present have changed to the non-ionized condition.
This behaviour is explained by considering the non-ionized part of the diazonium hydroxide to exist in solution in a hydrated form, the equation of equilibrium being: C6H6.N.
The ionized condition must be supposed to last to a greater or less extent for a good many hours to account for aurora being seen throughout the whole night.
It is one of the "strong" acids, being ionized to the extent of about 91.4% in decinormal solution.
The acid is a "weak" acid, being ionized only to a very slight extent in dilute aqueous solution.
Hydrobromic acid is one of the "strong" acids, being ionized to a very large extent even in concentrated solution, as shown by the molecular conductivity increasing by only a small amount over a wide range offdilution.
The boric acid being scarcely ionized gives only a very small quantity of hydrogen ions, whilst the base (sodium hydroxide) produced by the hydrolysis occasioned by the dilution of the solution, being a "strong base," is highly ionized and gives a comparatively large amount of hydroxyl ions.