Thermal diffusion with hydrolysis in aqueous solutions of sodium carbonate

1991 ◽  
Vol 69 (10) ◽  
pp. 1584-1588 ◽  
Author(s):  
Hui Lü ◽  
Derek G. Leaist
Keyword(s):  
Steady State ◽  
Aqueous Solutions ◽  
Thermal Diffusion ◽  
Sodium Carbonate ◽  
Soret Coefficient ◽  
Mixed Electrolytes ◽  
Cold Plate ◽  
Aqueous Sodium ◽  
Aqueous Sodium Carbonate ◽  
Nonisothermal Conditions

A conductimetric technique is used to measure thermal diffusion in aqueous solutions of sodium carbonate. In dilute solutions hydrolysis produces significant amounts of sodium bicarbonate and sodium hydroxide: Na2CO3 + H2O = NaHCO3 + NaOH. The applied temperature gradient causes the various solutes to migrate to the cooler parts of the solution. NaOH is found to diffuse more rapidly than NaHCO3, leading to the accumulation of excess NaOH (relative to NaHCO3) at the cold plate. Binary Na2CO3(m) + H2O mixtures therefore separate into ternary Na2CO3(m1) + NaOH(m2) + H2O mixtures under nonisothermal conditions. The steady-state molality gradients dm1/dT and dm2/dT and the ternary heats of transport of aqueous Na2CO3 and NaOH are reported. Key words: aqueous sodium carbonate, hydrolysis, mixed electrolytes, Soret coefficient, thermal diffusion.

Fluorometric Determination of Chlortetracycline in Low Level Mixed Feeds

1964 ◽  
Vol 47 (6) ◽  
pp. 1157-1161
Author(s):  
Stanley E Katz ◽  
Joseph Spock
Keyword(s):  
Ion Exchange ◽  
Sodium Carbonate ◽  
Fluorometric Determination ◽  
Aqueous Sodium ◽  
Exchange Column ◽  
Aqueous Sodium Carbonate ◽  
Ion Exchange Column ◽  
Low Levels ◽  
Mixed Feeds

Abstract The fluorometric determination of low levels of chlortetracycline in mixed feeds is based upon the separation of the chlortetracycline on a Decalso ion exchange column after extraction from the feed. The chlortetracycline is eluted from the resin after conversion to isochlortetracycline by hot aqueous sodium carbonate. The isochlortetracycline is measured fluorometrically. Results agree with microbial assays.

Densities and compressibilities of aqueous sodium carbonate and bicarbonate from 0 to 45�C

1983 ◽  
Vol 12 (4) ◽  
pp. 233-254 ◽  
Author(s):  
J. Peter Hershey ◽  
Sara Sotolongo ◽  
Frank J. Millero
Keyword(s):  
Sodium Carbonate ◽  
Aqueous Sodium ◽  
Aqueous Sodium Carbonate

Aza-Michael reaction promoted by aqueous sodium carbonate solution

2013 ◽  
Vol 54 (21) ◽  
pp. 2669-2673 ◽  
Author(s):  
Xiao-Ji Tang ◽  
Zhao-Lei Yan ◽  
Wen-Liang Chen ◽  
Ya-Ru Gao ◽  
Shuai Mao ◽  
...  
Keyword(s):  
Sodium Carbonate ◽  
Sodium Carbonate Solution ◽  
Michael Reaction ◽  
Carbonate Solution ◽  
Aqueous Sodium ◽  
Aqueous Sodium Carbonate

Thermal Diffusion of Weak Electrolytes III. The Soret Coefficients of Normal Carboxylic Acids

2000 ◽  
Vol 214 (1) ◽  
Author(s):  
L. Domonkos ◽  
J. Liszi
Keyword(s):  
Formic Acid ◽  
Aqueous Solutions ◽  
Carboxylic Acids ◽  
Thermal Diffusion ◽  
Soret Coefficient ◽  
Conductometric Method ◽  
New Model ◽  
Weak Electrolytes

A conductometric method is described and applied for the determination of the Soret coefficient of normal carboxylic acids in aqueous solutions in order to check a new model described in our previous papers. The Soret cell originally developed by Agar and Turner was applied with only minor modifications. The results show that the deviations between the measured and calculated Soret coefficients are lower than 2.5% except for formic acid (33% in average).

The Properties of β-Glucans from Different Fractions of Hull-Less Barley

2011 ◽  
Vol 365 ◽  
pp. 338-341 ◽  
Author(s):  
Xue Ling Zheng ◽  
Li Min Li ◽  
Qi Wang
Keyword(s):  
Sodium Carbonate ◽  
High Purity ◽  
Barley Cultivar ◽  
Aqueous Sodium ◽  
Aqueous Sodium Carbonate

Crude β-glucans were prepared from hull-less barley roller-milled fractions by aqueous sodium carbonate ( pH10). β-Glucan preparations from hull-less barley roller-milled fractions had high purity (90.88-95.04%). The Mw of β-glucan preparations from roller-milled fractions was ranging from 117,600 to 852,400 g/mol, For the same hull-less barley cultivar, β-glucan from flour had higher Mw than shorts and bran, and β-glucan preparations from bran had the lowest Mw.

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