Determination of chlorine content in 1,3,5-triamino-2,4,6-trinitrobenzene by converting it into 1,3,5-trihydroxy-2,4,6-trinitrobenzene by treatment with aqueous sodium hydroxide

The Analyst ◽  
1998 ◽  
Vol 123 (2) ◽  
pp. 397-398 ◽  
Author(s):  
Mehilal ◽  
R. N. Surve ◽  
J. P. Agrawal
Keyword(s):  
Sodium Hydroxide ◽  
Aqueous Sodium Hydroxide ◽  
Chlorine Content ◽  
Aqueous Sodium

The retroaldol reaction of 3-methyl-2-butenal

1983 ◽  
Vol 61 (1) ◽  
pp. 171-178 ◽  
Author(s):  
J. Peter Guthrie ◽  
Brian A. Dawson
Keyword(s):  
Sodium Hydroxide ◽  
Equilibrium Constant ◽  
Rate Constants ◽  
Equilibrium Constants ◽  
Aqueous Sodium Hydroxide ◽  
Initial Increase ◽  
Aqueous Sodium ◽  
Rate Determining Step ◽  
Kinetics Of

In aqueous sodium hydroxide solutions at 25 °C, 3-methyl-2-butenal, 1c, undergoes retroaldol cleavage to acetone and acetaldehyde. The kinetics of the retroaldol reaction were followed spectrophotometrically at 242 nm and showed simple first order behavior. When 3-methyl-3-hydroxybutanal, 2c, was added to aqueous sodium hydroxide solutions at 25 °C, there was an initial increase in absorbance at 242 nm, attributed to formation of 1c, followed by a 20-fold slower decrease; the rate of the slow decrease matches the rate of disappearance of 1c under the same conditions. Analysis of the kinetics allows determination of the three rate constants needed to describe the system: khyd = 0.00342; kdehyd = 0.00832; kretro = 0.0564; all M−1 s−1. The equilibrium constant for enone hydration is 0.41. Rate constants for the analogous reactions for acrolein and crotonaldehyde could be obtained from the literature. There is a reasonable rate–equilibrium correlation for the retroaldol step. For the enone hydration step, rate and equilibrium constants respond differently to replacement of hydrogen by methyl. It is proposed that this results from release of strain after the rate-determining step by rotation about a single bond; this decrease in strain is reflected in the equilibrium constant but not in the rate constant.

THE DETERMINATION OF OESTROGENS IN BODY FLUIDS

1954 ◽  
Vol 11 (2) ◽  
pp. 189-196 ◽  
Author(s):  
HANNELORE BRAUNSBERG ◽  
MARGARET I. STERN ◽  
G. I. M. SWYER
Keyword(s):  
Stationary Phase ◽  
Sodium Hydroxide ◽  
Chromatographic Separation ◽  
Aqueous Sodium Hydroxide ◽  
Body Fluids ◽  
Aqueous Sodium ◽  
Elution Pattern ◽  
Phenolic Extract

SUMMARY A micro-method is described for the chromatographic separation of oestrone, oestradiol and oestriol from a phenolic extract of body fluids. The stationary phase is 3·1n aqueous sodium hydroxide held by Celite 535 as the supporting medium. Oestrone and oestradiol are eluted with benzene:petroleum ether, b.p. 60–80° C, 4:1 (v/v), and oestriol with a 17:3-chloroform:butanol mixture. A diagram of the apparatus used is shown. The elution pattern, and data showing how it changes with temperature, are included.

Ion association of dilute aqueous sodium hydroxide solutions to 600�C and 300 MPa by conductance measurements

1996 ◽  
Vol 25 (8) ◽  
pp. 711-729 ◽  
Author(s):  
Patience C. Ho ◽  
Donald A. Palmer
Keyword(s):  
Sodium Hydroxide ◽  
Ion Association ◽  
Aqueous Sodium Hydroxide ◽  
Aqueous Sodium

scholarly journals Triple Helix of Scleroglucan in Dilute Aqueous Sodium Hydroxide

1981 ◽  
Vol 13 (12) ◽  
pp. 1135-1143 ◽  
Author(s):  
Toshio Yanaki ◽  
Takemasa Kojima ◽  
Takashi Norisuye
Keyword(s):  
Sodium Hydroxide ◽  
Triple Helix ◽  
Aqueous Sodium Hydroxide ◽  
Aqueous Sodium
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