Liebig method

Proximate analysis, determination of moisture content of the general analysis sample of coke Proximate analysis, determination of volatile matter content Proximate analysis, determination of ash content Determination of gross calorific value Ultimate analysis of coal and coke, determination of carbon and hydrogen content, high temperature combustion method Liebig method... 

As far as the utilization of chlorine is concerned, Liebig s method is very uneconomic. As we can see from the equation (XVII-7), only one sixth of the chlorine introduced is utilized for the manufacture of chlorate, whilst the remaining five sixths are converted into almost worthless calcium chloride. Therefore this method is seldom used, as it cannot compete with the modern electro-lytical method of manufacturing chlorate the production costs of which are only one third of the cost of the Liebig method. 

Sulphur by the Liebig Method.—By the Liebig method the compound is fused, with sodium or potassium hydroxide, in a silver crucible. When fused, a little potassium nitrate is added as an oxidizing agent. The sulphur of the organic compound is thus converted into sodium or potassium sulphate. The fused mass is dissolved in water, acidified with nitric acid, and the sulphur precipitated as barium sulphate by the addition of barium nitrate. 

Determination of the HCN content of HNCO. A thin jet of 1 ml. of HNCO is added from a precooled pipette to 40 ml. of (PC, IN, vigorously shaken KOH solution. The HNCO is absorbed as cyanate. The CN ion is titrated with silver nitrate solution by the Liebig method. 

ISO. 201 In. Coal and Coke—Determination of Carbon and Hydrogen, Liebig Method (ISO 609). International Standards Organization, Geneva, Switzerland. 

Sulphuric acid method. Place 20 g. of commercial cycZohexanol and 0-6 ml. of concentrated sulphuric acid in a 150 or 200 ml. round-bottomed or bolt head flask, add 2-3 chips of porous porcelain, and mix well. Fit the flask with a fractionating column, a Liebig condenser, adapter and filter flask receiver as in Section 111,10 (1). Heat the flask in an air bath (Fig. II, 5, 3) at such a rate that the temperature at the top of the column does not rise above 90° alternatively, an oil bath, heated to a temperature of 130-140°, may be used. Stop the distillation when only a small residue remains and the odour of sulphur dioxide is apparent. Transfer the distillate to a small separatory funnel. 

The method may also be applied to the analysis of silver halides by dissolution in excess of cyanide solution and back-titration with standard silver nitrate. It can also be utilised indirectly for the determination of several metals, notably nickel, cobalt, and zinc, which form stable stoichiometric complexes with cyanide ion. Thus if a Ni(II) salt in ammoniacal solution is heated with excess of cyanide ion, the [Ni(CN)4]2 ion is formed quantitatively since it is more stable than the [Ag(CN)2] ion, the excess of cyanide may be determined by the Liebig-Deniges method. The metal ion determinations are, however, more conveniently made by titration with EDTA see the following sections. 

The third method of making internal seak is not so widely applicable as the previous two, but it is very useful for certain joints. It is best described in terms of one of its uses—m the manufacture of a Liebig condenser. 

The type of double surface condenser most often found in laboratories is the Davies improved double surface condenser which appeared in 1905, and was designed by J. Davies of A. Gallenkamp Co. as a direct development from Thresh s modification of the Bidet condenser. All rubber bungs and tubing were eliminated in the Davies condenser, which has retained its popularity for 50 years. To make a condenser of this kind the inner water jacket is connected to the outer one by two internal seals wWch are made by a sli t modification of Method 2 described on p. 75. The rest of the assembly is similar to that for an ordinary Liebig condenser. 

Scheme 2 shows preparation of the biftinctional fiber. PPPE-c and PPPE-f grafted with CMS and ST were functionalized by the reported method.6 Here, an example of functionalization procedures is described. The precursory fibers (PPPE-f grafted with CMS and ST, 2 g) and triethyl phosphite (60 ml) were taken into a three-necked flask (200 ml) equipped with a Liebig condenser. After the mixture in the flask was heated for 48 h at 100 °C, the resulting phosphorylated PPPE-f was washed with acetone, aceton-water mixture and water, and dried in vacuum oven at 40 °C. In order to introduce sulfonic acid groups, the phosphorylated PPPE-f was treated with a 30 mL of 1,2-dichloroethane solution of chlorosulfonic acid (10 wt %) for 2 h at room temperature. Finally, diethyl phosphonate groups on the fibers were hydrolyzed with 12 M hydrochloric acid under refluxed... 

H Kunz, H-H Bechtolsheimer. Synthesis of sterically hindered peptides and depsipep-tides by an acid chloride method with 2-phosphonioethoxycarbonyl-(Peoc)-amino acids and hydroxy acids. Liebigs Ann Chem 2068, 1982. 

Pepin Lehalleur (Ref 17, pp 143—44) described Liebig s and Chandelon s methods of manuf which have been used in France... 

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