In this process cellulose (in the form of sawdust) is made into a stiff paste with a mixture of strong caustic potash and soda solution and heated in flat iron pans to 20o-250 C. The somewhat dark-coloured mass is lixiviated with a small amount of warm water in order to remove excess of alkali, the residual alkaline oxalates converted into insoluble calcium oxalate by boiling with milk of lime, the lime salt separated, and decomposed by means of sulphuric acid.
CH 2 CH 2 ' and from the condensation of ethyl oxalate with esters of other dibasic acids in presence of sodium ethylate (W.
With fused potash it forms potassium oxalate and acetate.
The simplest of all include: (z) the synthesis of sodium oxalate by passing carbon dioxide over metallic sodium heated to 3500 - 360'; (2) the synthesis of potassium formate from moist carbon dioxide and potassium, potassium carbonate being obtained simultaneously; (3) the synthesis of potassium acetate and propionate from carbon dioxide and sodium methide and sodium ethide; (4) the synthesis of aromatic acids by the interaction of carbon dioxide, sodium and a bromine substitution derivative; and (5) the synthesis of aromatic oxy-acids by the interaction of carbon dioxide and sodium phenolates (see Salicylic Acid).
The crude oxide of the metal is obtained from cerite, by evaporating the mineral with strong sulphuric acid, removing excess of acid and dissolving the residue in ice-cold water; sulphuretted hydrogen is passed through the solution, which is then filtered, acidified with hydrochloric acid, and precipitated as oxalate by oxalic acid; the oxalate is then converted into oxide by ignition.
The urea oxalate is recrystallized and decolorized and finally decomposed by calcium carbonate (J.
One method for this purpose is to convert it into a solution of the nitrate U02(N03)2, and from it to precipitate the metal as oxalate by oxalic acid (Peligot).
The perfectly pure metal may be prepared by heating the oxide or oxalate in a current of hydrogen; when obtained at a low temperature it is a black powder which oxidizes in air with incandescence; produced at higher temperatures the metal is not pyrophoric. Peligot obtained it as minute tetragonal octahedra and cubes by reducing ferrous chloride in hydrogen.
In chloroform solution it combines with anhydrous oxalic acid to form a compound, Sb2C18(C204), which is to be considered as COOSbC14 tetra-chlorstibonium oxalate I (R.
By heating a mixture of cobalt oxalate and sal-ammoniac in air, it is obtained in the form of minute hard octahedra, which are not magnetic, and are only soluble in concentrated sulphuric acid.