Abstract The color development degree of phenol with iron salts is affected by the order of reagent addition and the type of anions in the iron salts. Different orders of adding phenol solution and FeCl3 solution result in different color development outcomes. Experimental investigation using the controlled variable method confirmed that the color development results were jointly influenced by three factors: solution pH, ionic strength, and Cl- concentration. When phenol reacted with iron salts containing different anions, the purple color showed varying depths, which was related to both the coordination ability of the anions and the ionic strength. Through experiment, it was concluded that the coordination substitution between anions was the main reason for the different depths of purple color when phenol reacted with different iron salts. Further investigation was conducted to optimize the best experimental conditions for the color reaction between phenol and FeCl3 solution.
LIN Qian-Nan. Experimental Inquiry on Influencing Factors of Color Development Between Phenol and Iron Salts[J]. Chinese Journal of Chemical Education, 2026, 47(5): 105-110.
