Approximate molecular weights from the boiling-point rise: A laboratory experiment in elementary chemistry

1930 ◽  
Vol 7 (11) ◽  
pp. 2715
Author(s):  
Arthur Rose ◽  
R. D. Billinger
Keyword(s):  
Laboratory Experiment ◽  
Boiling Point ◽  
Molecular Weights

EBULLIOMETRY AND THE DETERMINATION OF THE MOLECULAR WEIGHTS OF POLYMERS: PART II. BACKGROUND NOISE IN THE SMALL EBULLIOMETER

1959 ◽  
Vol 37 (9) ◽  
pp. 1517-1526 ◽  
Author(s):  
W. R. Blackmore
Keyword(s):  
Boiling Point ◽  
Background Noise ◽  
Polymer Solutions ◽  
Liquid Surface ◽  
Pressure Fluctuations ◽  
High Polymer ◽  
Molecular Weights ◽  
Usual Form ◽  
Lower Background

It is shown that the usual form of ebulliometer is subject to at least three sources of noise. Those discussed here are (1) pressure fluctuations over the boiling liquid surface, (2) the Cottrell pump, and (3) the foam which appears on many polymer solutions when maintained at the boiling point. Background noise in this, and other ebulliometers commonly employed, may be large compared to the size of the signals expected for dilute high polymer solutions. Consequently further progress in ebulliometry is dependent on the development of a new ebulliometer with a much lower background noise.

XIII.—A Method for Determining the Molecular Weights of Dissolved Substances by Measurement of Lowering of Vapour Pressure

1912 ◽  
Vol 31 ◽  
pp. 259-261
Author(s):  
Alan W. C. Menzies
Keyword(s):  
Vapour Pressure ◽  
Boiling Point ◽  
Molecular Weights

Although various methods have from time to time been described for determining the molecular weights of dissolved substances by measurement, not of boiling-point elevation, but of the reduction of vapour pressure of a solvent due to the presence of a dissolved substance, none of these methods has come into general use. The method here proposed, operating on this principle, offers the possibility of simply determining the molecular weights of non-volatile solutes in any of the ordinary solvents with an accuracy at least equal to that of the ebullioscopic methods, and in an apparatus at least as easily manageable.

scholarly journals X. Bakerian lecture .—On the Relations between the viscosity (internal friction) of liquids and their chemical nature

1894 ◽  
Vol 185 ◽  
pp. 397-710 ◽  
Keyword(s):  
Refractive Index ◽  
Chemical Composition ◽  
Internal Friction ◽  
Boiling Point ◽  
Chemical Nature ◽  
Point Of View ◽  
The Other ◽  
Directed Attention ◽  
Physical Constants ◽  
Molecular Weights

During the half century which has elapsed since Hermann Kopp directed attention to the connection which exists between the molecular weights of substances and their densities, the attempts which have been made to establish similar relationships between the magnitudes of other physical constants and chemical composition have shown that probably all physical constants are to be regarded as functions of the chemical nature of molecules, and that the variations in their magnitude observed in passing from substance to substance are to be attributed to changes in chemical composition. The physical properties first investigated from this point of view were naturally those either often measured or at least capable of being easily measured. To this class belong such determinations as density, boiling-point, refractive index, &c., &c. On the other hand, properties not so clearly understood, or less readily perceived, received little or no attention. An example of this kind occurs in connection with the viscosity of liquids.

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