Molar magnetic susceptibility experimental determination

In practical experiments, the magnetometer is normally calibrated such that the experimentally determined magnetisation can be converted into the molar magnetic susceptibility (xm) through multiplication by the ratio of the molecular weight to the sample weight and dividing by the applied... 

Most experimental results in the literature are expressed in terms of the quantities Xg or Xm- The system of units employed almost exclusively in the field of magnetism is therefore the electromagnetic cgs system. Thus the unit of Xg is 10 emu/g (10" cm /g) and that of Xm is 10" emu/mol (10 cm /mol). Similarly, the unit usually employed for M, and M is 10 Gau.ss-emu/g and 10 Gauss emu/mol, respectively. If a rationalized system of units would be chosen by defining B = H + M, the experimental results would have to be multiplied by 4tt. This is the case for SI units which are consequently little used in magnetic studies [98,99, 100], For the molar magnetic susceptibility, the conversion from SI to cgs units is determined by... 

The values of C and 0 are usually determined graphically from the straight line which fits best to the experimental 1/xm data plotted versus temperature (Curie-Weiss plot). The TIP contribution may be also obtained graphically if the molar magnetic susceptibility is plotted as function of 1/T and extrapolated for l/T- 0. Often No. is incorporated into Eq. (27), its numerical value being estimated on the basis of ligand field theory [22,45]. For methods to determine Na empirically, cf. [46,47]. 

Ionization constants of hydroxy- and mercaptopyridazines, ° of amino- and diaminopyridazines and their quaternization products,of methylsulfinylpyridazines," and of pyridazinium ylides have been recorded. The basicities of a series of pyridazines have been determined and correlated with substituent constants using the Hammett free-energy relationship. The magnetic susceptibility of pyridazine was measured, and the rate constant for the reaction of hydrogen atoms with pyridazine was determined. The experimental dipole moment, Kerr constant, and molar Cotton-Mouton constant, obtained at 298 K and 633 nm, are reported. The magnetic circular dichroism spectrum of pyridazine has been measured. ... 

In principle at least, Eq. (11) provides means for the quantum mechanical calculation of magnetic susceptibility. However, at present theoretical results are of no significance in experimental work. Instead of direct calculation use is often made of the law of additivity of atomic diamagnetic susceptibilities. According to Pascal [14,169], the molar diamagnetic susceptibility of a pure compound is approximately determined by... 

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