Sodium bismuthate dihydrate is primarily used in analytical chemistry as a strong oxidizing agent. It is particularly effective in the qualitative analysis of manganese, where it oxidizes manganese compounds to permanganate, allowing for easy detection and measurement. This property makes it valuable in laboratory settings for identifying and quantifying manganese in various samples. Additionally, it is utilized in organic synthesis for oxidation reactions, where it can selectively oxidize certain functional groups in complex molecules. Its oxidizing capabilities also extend to environmental applications, such as in the treatment of water to remove contaminants through oxidation processes. Overall, it serves as a versatile reagent in both analytical and synthetic chemistry.