As a subject matter expert in the field of chemistry and environmental science, I can provide you with a detailed explanation of how to obtain pure oxygen. The most common method for obtaining pure oxygen is through the process of electrolysis. This process involves the following steps: 1. Separation: The first step is to separate oxygen from other gases in the air. This is typically done by compressing air and cooling it to liquefy it, which allows for the separation of oxygen from nitrogen and other gases due to their different boiling points. 2. Electrolysis: Once the oxygen is separated, it can be further purified through electrolysis. This involves passing an electric current through a solution of water (H2O) or a molten compound containing oxygen, such as sodium chloride (NaCl). The electric current causes the water molecules to split into their constituent elements, hydrogen (H2) and oxygen (O2). 3. Collection: The resulting hydrogen and oxygen gases are then collected separately. Since oxygen is the gas we are interested in, it is collected and further purified if necessary. 4. Purification: The collected oxygen may still contain trace amounts of other gases. To ensure purity, it can be passed through a series of filters or scrubbers that remove any remaining contaminants. 5. Storage: Finally, the pure oxygen is stored in specialized containers that are designed to handle high-pressure gases. It's important to note that while photosynthesis does produce oxygen as a byproduct, it is not a practical method for obtaining pure oxygen for most industrial or medical applications. read more >>

The most common natural method is photo-synthesis, in which plants use sunlight convert carbon dioxide in the air into oxygen. This offsets the respiration process, in which animals convert oxygen in the air back into carbon dioxide. ... This method is called electrolysis and produces very pure hydrogen and oxygen.read more >>