Indifferent nitrogen

If a given unknown containing indifferent nitrogen is a colorless compound, it is advisable to apply first the hydrolysis test for Subgroup B. On the other hand, colored compounds should be subjected to reduction tests before resorting to those involving hydrolysis. Often a combination of the two tests is advisable, alkaline hydrolysis being resorted to when no definite results are obtained by acid hydrolysis. 

Substances which decompose (or otherwise change) in contact with air must be recrystallised in an indifferent atmosphere, such as carbon dioxide, nitrogen or hydrogen. The apparatus of Fig. 

Materials. Synthetic hematite was obtained from J. T. Baker Chemical Company, Phillipsburg, NJ. Particle size analysis using a HIAC instrument (Montclair, CA) indicated the particles to be 80 percent (number) finer than 2 microns. Using nitrogen as the adsorbate, the B.E.T. specific surface area was found to be 9 square meters per gram. The point of zero charge, as obtained from electrophoretic measurements in the presence of indifferent electrolytes, occurred at pH 8.3. 

Nitrogen sulphide acts slowly on the acids of the paraffin series. In the case of acetic acid there is an evolution of sulphur dioxide, and sulphur and ammonium sulphate are obtained, as well as small quantities of free nitrogen. Considerable quantities of acetamide and diacetamide are also formed.7 The sulphide is indifferent towards primary and secondary bases of the aromatic scries and towards all tertiary bases.8 Nitrogen sulphide has been claimed to assist the vulcanisation of rubber. 

Van Laar,2 ftom the basis flfi2=A/( i 2) ( 35.VTI C), deduced a complicated equation for the change of vapour pressure from po to Pi caused by the pressure p of an indifferent gas, and showed that it agreed vwith Bartlett s observation that the vapour pressure of water is increased to four times its normal value by a pressure of 1000 atm. of nitrogen. Van Laar s equation is ... 

Nickel oxide is reduced in a combustion tube by a stream of hydrogen at 350°.166 The material is allowed to cool in a stream of hydrogen after the reaction has penetrated the interior. Then the hydrogen is replaced by a stream of nitrogen. It is advisable to have an atmosphere of inert gas present when adding the catalyst to the substance to be hydrogenated. Freshly reduced nickel loses its activity if exposed to air and therefore, if not used at once, must be kept in an indifferent atmosphere or in a vacuum alternatively it can be stored in methanol, ethanol, or benzene. 

This is an interesting, if not very straightforward notion. Why should particles of A (e.g. nitrogen) repel other A particles but not particles of B, such as oxygen, toward which they remain indifferent ... 

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