Effect of halide ions on the dissolution of copper single crystal planes in dilute sulfuric acid

Dissoln. rates of Cu single crystals in 0.1N H2SO4 contg. 1 × 10-​8 M Cl-​, Br-​, or I-​, were detd. at 30°. The rates, which are controlled by transport process in soln., are a function of the temp., stirring rate, O soly., crystallog. orientation, and halide ion concn. Halide ions acted as an anodic inhibitor at low concns., and cathodic inhibitor at high concns. The changes in dissoln. rates were attributed to adsorption of halide ions or pptn. of Cu+ halides on the surface of the crystallog. planes