Abstract Through experiments and the Nernst equation, it has been proven that at room temperature and in the absence of oxygen, copper undergoes a displacement reaction with concentrated hydrochloric acid, resulting in the formation of monovalent copper complexes and hydrogen gas; at room temperature and in aerobic (air) conditions, the reaction of copper with dilute hydrochloric acid is beneficial to the formation of divalent copper, while copper reacts with hydrochloric acid of relatively not very low concentration to preferentially produce monovalent copper. The displacement reaction between metal and acid is related to many factors, such as the activity of metal, the concentration of H+, the species and concentration of acid radical ions, and the morphology or solubility of metal ions in the product. It is suggested that the inference “in the order of metal activity, the metal behind hydrogen cannot replace hydrogen from acids” should be used with caution in teaching.
WANG Xue-Rui, LIU Song-Wei, SUN Jing-Yan. Experimental Inquiry on Reaction Between Copper and Hydrochloric Acid[J]. Chinese Journal of Chemical Education, 2025, 46(17): 95-101.
