Abstract This study systematically compared the differences in hydrolysis behavior between ferric nitrate, ferric chloride, and ferric sulfate at the same concentration in response to revisions to the hydrolysis investigation experiment in the new textbook. Through multi-dimensional experiments involving pH, color, light transmittance, and absorbance, it was found that: the coordination interaction between chloride ions and iron ions inhibited the forward shift of the iron ion hydrolysis equilibrium and affected changes in solution color, interfering with students’ judgment of the hydrolysis equilibrium; Sulfate ions exhibited a dual effect: they not only formed complexes with iron ions to inhibit their hydrolysis to some extent but also promoted the formation of precipitates, aiding students in assessing the hydrolysis equilibrium. This study not only provides experimental evidence for selecting ferrous sulfate instead of ferric chloride for hydrolysis exploration experiments in textbooks, but also experimentally demonstrates that ferric nitrate and ferric sulfate solutions are unsuitable for colloid preparation, whereas ferric chloride solution is more suitable for preparing colloids.
ZHANG Qian-Yong, LI Gui-Xin, DONG Ling. Series of Experiments Deeply Exploring Influencing Factors of Hydrolysis of Ferric Salts[J]. Chinese Journal of Chemical Education, 2026, 47(5): 94-99.
