Nomographs for Determining Molecular Weights by the Freezing Point and Boiling Point Methods

1936 ◽  
Vol 8 (3) ◽  
pp. 228-228 ◽  
Author(s):  
W. S. Gilfoil
2019 ◽  
Vol 10 (01) ◽  
pp. 20-27
Author(s):  
Dian Kurnia Sari ◽  
Rian Ternando

Minyak bumi dievaluasi guna menentukan potensi minyak bumi sebagai bahan baku kilang minyak untuk menghasilkan fraksi yang dikehendaki. Evaluasi yang dilakukan meliputi pengujian sifat umum minyak bumi, klasifikasi minyak bumi dengan distilasi True Boiling Point (TBP) wide cut (pemotongan jarak lebar) serta analisis fraksi kerosin. Fraksi kerosin yang dihasilkan dari primary process dapat diolah menjadi bahan bakar rumah tangga (minyak  tanah) dan bahan bakar lampu penerangan. Selain itu fraksi kerosin juga dapat dioalah menjadi bahan bakar untuk pesawat terbang jenis jet (avtur). Avtur adalah kerosin yang dengan  spesifikasi yang diperketat, terutama mengenai titik uap dan titik beku. Untuk melakukan pengolahan pada minyak bumi perlu diketahui karakteristik dan spesifikasi minyak  bumi (bahan baku) yang akan diolah untuk mengetahui mutu dan manfaat minyak bumi tersebut. Salah satu parameter uji analisis minyak bumi yaitu parameter sifat fisika. Dari data distilasi TBP diperoleh persentase fraksi kerosin Crude Oil 99 PT HS sebesar 29 % vol sedangkan Crude Oil 165 PT RT sebesar 23 % vol. Berdasarkan analisis sifat fisika yang meliputi Specific Gravity, Refractive Index nD20, Freezing Point, Smoke Point, Flash Point “Abel”, Aniline Point, Copper Strip Corrosion, Kinematic Viscosity dan Characterization KUOP. Crude Oil 99 dan Crude Oil 165 memiliki mutu yang baik serta memenuhi spesifikasi produk kerosin maupun produk avtur.


1934 ◽  
Vol 7 (1) ◽  
pp. 34-39 ◽  
Author(s):  
A. J. Wildschut

Abstract The determination of the chain-length of high molecular substances, as, e.g., rubber and gutta-percha, has lately been the subject of many investigations, though as yet the problem has not been definitely solved. The ordinary methods—measurements of the raising of the boiling point and of the depression of the freezing point—can be used only for molecular weights of some thousands, and there always remains a large gap between these compounds and the far greater natural ones. To bridge over this gap Staudinger has developed a supposition according to which it is possible to determine very high molecular weights by means of a viscosimetric method. This method depends on the known fact that for dilute solutions, in which the molecules do not hinder each other (so-called sol-solutions), the specific viscosity is proportional to the length of the molecule. For homologs we have:


1946 ◽  
Vol 24f (5) ◽  
pp. 287-299 ◽  
Author(s):  
K. A. Clendenning ◽  
D. E. Wright

Freezing point, viscosity, and boiling point data are presented for aqueous solutions of levo-2,3-butanediol containing methanol, ethanol, ethylene glycol, and tetrahydrofurfuryl alcohol as third components. All four ternary systems show freezing points of −50 °C. and lower over a considerable range of compositions. Among the compounds tested as third components, methanol was most effective as a thinning agent and accessory freezing point depressant. The data indicate that 20% methanol–40% butanediol–40% water is suitable for use at temperatures as low as −50 °C.


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