Oxalic acid, preparation properties

Preparation of Carbon(II) Oxide from Oxalic Acid and Studying Its Properties. Assemble an apparatus as shown in Fig. 104, sub-... 

In a series of transition metal oxide semiconductor powders, photochemical activity in the decarboxylation of oxalic acid was controlled by surface properties and the presence of recombination centers, which in turn depended on the preparation method Similar effects have also been noted in the photodecarboxylation of pyruvic acid and formic acid... 

In 1895 Dull,9 who was studying inulin and its products of hydrolysis, found that when either fructose or sorbose was treated with an aqueous solution of oxalic acid under pressure, a substance was obtained which had the formula CeHeOa and resembled furfural in its properties. This substance was further investigated by Kiermayer4 who found that fructose and sucrose were the best sources when they were heated with 0.3% aqueous oxalic acid at 120°. It was however only the fructose portion of the sucrose molecule which was transformed since the glucose moiety was recovered unchanged. Kiermayer prepared several derivatives of CeH Os and from its reactions concluded that its structure was probably /3-hydroxy-S-methylfurfural (III). Van Ekenstein and... 

The copper-zinc [ex carbonate] catalysts, prepared by the conventional precipitation technique using Na2C03 often described in literature [6,12], lead to efficient catalysts containing, despite washing of the precipitate, small amounts of sodium (0.05-0.1 wgt%) able to change the properties of the catalytic system [13]. To make a fair comparison with a Na free Cu-La-Zr catalysts Cu-Zn [ex oxalate] catalysts samples were prepared using the precipitation with oxalic acid described in the experiment part. 

Thermal properties can also be influenced by a furan ring in the para position of a phenolic ring. A phenolic novolac was prepared by reaction of phenol with methanal using oxalic acid as catalyst, and the furfuryl alcohol was added in a proportion of 0.5 mole furfuryl alcohol per mole phenol. The reaction steps in Scheme 11 show that the condensation of furfuryl alcohol at the para position of the phenolic rings is accompanied by the self-condensation of furfuryl alcohol. 

A silica-based sorbent-anion complexone polymer coating [24]ane-N6 macrocycle was prepared. The chelation properties of this material were investigated for Cu(II), Cd(II), Co(II), and Zn(II). Oxalic acid was found to be the most effective eluent for the separation of these metal ions from seawater. The limits of these metal ions were identified to be 5 x 10 M, 1 x 10 M, 3 x 10 M, and 2 X 10 M for Cu(II), Cd(II), Co(II), and Zn(II), respectively. ... 

The redox electrochemistry of a Fe /Fe couple is easily accomplished on a phthalocyanine-coated electrode with peak separations comparable to that of platinum [141,142,163,164]. Phthalocyanine-coated electrodes are found to be efficient electrocatalysts to catalys catechol, p-benzoquinone and oxalic acid oxidations [120,150]. The electrochemical activity of these electrodes may be due to the high voltage, surface area, high electronic conductivity and redox behaviour of phthalocyanine, vanadium phthalocyanine and other phthalocyanines have been prepared by vapour deposition and show photoelectrochemical responses when dipped in aqueous electrolytes [244-249]. Polymeric phthalocyanines of Co and Fe are coated on active carbon and are shown to give catalytic properties for dioxygen reduction and thiol oxidations. Dioxygen chemisorption and ammonia absorption of metallo... 

The polymerization temperature has a substantial influence on the kinetics of polymerization as well as on the conductivity, redox properties, and mechanical characteristics of the films. The rate of polymerization is strongty affected by the temperature of synthesis [587-589]. The generation temperature also affects the conductivity of the resulting polymer. In general, higher conductivities are obtained at lower temperatures, both in aqueous media [577] and in propylene carbonate [590]. Films prepared in a propylene carbonate solution at —20°C are much more conductive than those prepared at 20°C. Mirebeau [591] has studied the effect of temperature and current density on the polymerization of pyrrole on stainless steel from propylene carbonate solutions. On aluminum electrodes. Beck et al. [550,555] have shown that lower temperatures are also advantageous and that at 0°C smooth and strongly adherent potypyrrole layers are obtained from oxalic acid aqueous solutions. 

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