
TY  - JOUR
A1  - Srivastava, KC 
A1  - Banerji, SK 
T1  - Chelate formation between lead(II) and 1,2,5,8-tetrahydroxyanthraquinone (quinalizarin): Spectrophotometric studies on the composition and stability
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1967
VL  - 20
IS  - 7
SP  - 1385
EP  - 1394
KW  - 
UR  - https://doi.org/10.1071/CH9671385 
N2  - The formation of a bluish violet chelate between bivalent lead and 1,2,5,8-tetrahydroxyanthraquinone (quinalizarin) with maximum absorption at 520m&#956; has been studied. The chelate is soluble in aqueous ethanol. The composition of the chelate has been determined by three methods. The chelate has a composition of 1 : 1 and is stable at pH 6.1-8.5. The values of log K determined in 50% ethanolic medium by the method of Dey et al., the continuous variation method, and the mole ratio method, using absorbance data, are 4.1 ± 0.1, 4.0 ± 0.0, and 4.1  ± 0.1 respectively at 30°, pH 6.3. The free energy change of formation, calculated from the three values of log K, is -5.7 ± 0.1, -5.6 ± 0.0, and -5.7 ± 0.1 kcal respectively. 
ER  -

