The speed of sound in a medium depends on various factors, including the properties of the medium itself. In the case of gases, such as oxygen and air, the speed of sound is influenced by their molecular composition and the conditions in which they exist.
Air is a mixture of gases, predominantly composed of nitrogen (approximately 78%) and oxygen (about 21%), along with trace amounts of other gases. The speed of sound in air is determined by the average molecular mass and the intermolecular forces between the gas molecules.
When compared to air, pure oxygen (O2) has a higher molecular mass. The increased molecular mass affects the speed of sound because the speed is inversely proportional to the square root of the molecular mass. This means that gases with higher molecular masses tend to have slower speeds of sound.
Additionally, the intermolecular forces between oxygen molecules can also play a role. Oxygen molecules are more strongly attracted to each other compared to the nitrogen molecules in air. These intermolecular forces can slightly reduce the speed of sound in oxygen.
Therefore, due to its higher molecular mass and the nature of intermolecular forces, the speed of sound in pure oxygen is lower compared to the speed of sound in air.