Definitions

gravimetrically

Uranyl zinc acetate

Uranyl zinc acetate (ZnUO2(CH3COO)4)is a compound of uranium.

Uranyl zinc acetate is used as a laboratory reagent in the determination of sodium concentrations of solutions using a method of quantitatively precipitating sodium with uranyl zinc acetate and gravimetrically determining the sodium as uranyl zinc sodium acetate, (UO2)2ZnNa(CH3COO)-6H2O. This method was important to determine Na in urine for diagnostic purposes. Zinc uranyl acetate is sometimes called "sodium reagent" since pale yellow NaZn(UO2)3(C2H3O2)9 is one of the very few insoluble sodium compounds.

The process for catalytic synthesis of toluene-2,4-diisocyanate (TDI) from dimethyl carbonate (DMC) consists of two steps. Starting from the catalytic reaction between toluene-2,4-diamine (TDA) and DMC, dimethyl toluene-2,4-dicarbamate (TDC) is formed, and then decomposed to TDI. For the first step, the yield of TDC is 53.5% at a temperature of 250 °C, over Zn(OAc)2/alpha–Al2O3 catalyst. For the second step, the yield of TDI is 92.6% at temperatures of 250–270 °C and under pressure of 2.7 kPa, over uranyl zinc acetate catalyst, when di-n-octyl sebacate(DOS) is used as heat-carrier, and a mixture of tetrahydrofuran (THF) and nitrobenzene is used as solvent.

References

  • Catalytic synthesis of toluene-2,4-diisocyanate from dimethyl carbonate, Wang Y.1; Zhao X.; Li F.; Wang S.1; Zhang J., Journal of Chemical Technology & Biotechnology, 2001, 78, 857-861.

Search another word or see gravimetricallyon Dictionary | Thesaurus |Spanish
Copyright © 2014 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature
FAVORITES
RECENT

;