QUANTITATIVE ANALYSIS 425 The practical limitations of the above methods are indicated in their detailed Description. Although certain of the above methods give results of high accuracy, it should 'be emphasised that very accurate determinations of molecular weights are not Dually required in organic chemistry, where the chief purpose of such deter-minations is to fix the molecular formula of a compound. Thus the quantitative €§ timation of the elements in a particular compound may show that the empirical formula is (C 3 H 5 Cl) n , and the molecular weight is then required in order to fix the value of n and hence the molecular formula. Molecular Weight Determinations by Physical Methods. Vapour Density. Victor Meyer's Method. Victor Meyer's method is almost universally employed for the determination of the vapour density of organic compounds. It has the advantages of requiring • very small quantity of the organic material, giving accurate results, and of being applicable to compounds the boiling-points of which lie over a wide range. It cannot however be applied to compounds which decompose on attempted
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This note was uploaded on 09/19/2011 for the course CHM 2211 taught by Professor Castalleano during the Fall '06 term at University of Florida.