Oxygen solubility in pure water and in dilute sulfuric acid solution has been studied as a part of atmospheric direct zinc leaching process development. The experimental results were compared with reference data and the Gibbs energy model. The dissolution dynamics of oxygen was further combined with the Gibbs energy minimization method. Together the experimental and model results give useful information and methodology for the developers of industrial processes related to gas solubility. The dynamic Gibbs energy calculation approach presented in this work extends the possibilities of evaluating changes in different process chemistries needed in process design.