CHEMICAL FORM OF COPPER(2) ACETATE IN ACETIC ACID SOLUTIONS

Potentiometric measurements with glass and copper electrodes in dry and wet acetic acid solutions, together with the corresponding spectrophotometric data, show that copper(II) acetate is predominantly dimeric in dry acetic acid solutions. The dissociation constant of the dimer increases as water is added, reaching (6 ± 3) × 10−4 at 3 M H2O. The dimer has an absorption maximum at 670 mμ with a molar absorptivity of 97.5 ± 2.5, while the monomer absorbs around 740 mμ with є740 – є500 = 39 ± 3. The equation log K =−5.0 + 4 log CH2O fits the data within experimental error over the range from 3 to 10 M H2O. © 1968, American Chemical Society. All rights reserved.