A systematic study was undertaken to determine the diffusion coefficient(D) for Cu+2 in the CuSO4-H2SO4 system at different Cu and H2SO4 concentrations and temperatures. An empirical equation for predicting theD value was developed and checked for its validity. Conductivities, densities, and viscosities of copper electrolytes were measured in a wide range of Cu and H2SO4 concentrations and temperatures and the results are reported. Such information also was gen-erated for complex solutions containing the impurities Ni, Co, Fe+2, Fe+3, and Mn. These prop-erties were calculated further using empirical equations and compared with the measured values.