ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

A potentiometric study of carbonation of lime with carbon dioxide in sucrose solution

R. Kohn and J. Vašátko

Slovak Academy of Sciences, Bratislava

Abstract: cf. C.A. 50, 12515a; 51, 7745b. Changes were studied of the potential (pH) of an Sb electrode during the reaction of Ca(OH)2 in sucrose soln. with CO₂ or oxalic acid (carbonation) at 20 and 85°. From the shape of the potentiometric titration curves, the formation of a complex Ca-saccharocarbonate (I), basic ppt. (II) and its decompn. during the carbonation can be estd. From the slope of the potential carbonation curve, as compared with the standard curve detd. by titration of I with HCl without formation of ppt., the amt. of Ca(OH)2 sepd. into II at any moment of carbonation can be calcd. The decrease of the stability of I and the formation of II detd. by potentiometric titration of clear Ca saccharate soln. contg. a small portion of I sol. in HCl or oxalic acid are shown. The shape of the potentiometric titration curves describing Ca(OH)₂ sepn. into II is dependent on acid, temp., and time of carbonation. I and II, which are pptd. during the carbonation, are unstable and their compn. changes with time. The potentiometric measurement of the carbonation describes the actual condition of the system at each moment, while the analytical detns. of the samples taken during the beet-sugar carbonation show the condition of the system after a certain time elapse.

Full paper in Portable Document Format: 112a84.pdf (in Slovak)

Chemical Papers 11 (2) 84–97 (1957)