The solubility of oxygen in pure or fresh water at 25 °C and 1.0 atm of O2 pressure is approximately 1.22 × 10−3 mol dm−3.
Here's a breakdown of oxygen solubility in water:
Oxygen Solubility Details
The solubility of oxygen in water is an important concept in various fields, including environmental science, biology, and chemistry. The amount of oxygen that can dissolve in water is limited and is affected by factors such as temperature, pressure, and the presence of other substances.
- Standard Conditions: At 25°C and under a partial pressure of 1.0 atm of oxygen, the solubility is around 1.22 × 10−3 mol/dm³.
- Variation: This solubility can vary slightly, with different literature sources reporting values ranging from 1.18 to 1.25 mol dm−3.
- Practical Implication: The relatively low solubility of oxygen in water is why aquatic organisms rely on specific adaptations (e.g., gills) to extract sufficient oxygen for respiration.
Factors Affecting Oxygen Solubility
Several factors influence how much oxygen can dissolve in water. Here are a few important ones:
- Temperature: As water temperature increases, the solubility of oxygen decreases. This is because gases are generally less soluble in warmer liquids.
- Pressure: Increased partial pressure of oxygen above the water will increase the amount of oxygen that dissolves in the water.
- Salinity: The presence of salts reduces the solubility of oxygen. For instance, oxygen dissolves less readily in seawater compared to freshwater.
- Other Dissolved Substances: Other substances in the water, such as organic pollutants, can also impact oxygen solubility by either directly affecting the saturation point or indirectly affecting the availability of oxygen due to consumption by bacteria.
Practical Insights
- Aquaculture: Understanding oxygen solubility is crucial in aquaculture. Proper aeration systems are essential in fish farms to maintain adequate dissolved oxygen levels for the health of the fish.
- Environmental Monitoring: Monitoring dissolved oxygen levels in natural water bodies is a critical component of assessing water quality. Low dissolved oxygen levels can indicate pollution and can be harmful to aquatic life.
- Industrial Processes: In industrial water treatment, understanding oxygen solubility helps determine the efficiency of aeration processes used to remove pollutants.
| Factor | Impact on Oxygen Solubility |
|---|---|
| Temperature | Decreases with increase |
| Pressure | Increases with increase |
| Salinity | Decreases with increase |
In summary, the solubility of oxygen in water is a key concept with practical implications across diverse fields, making it important to consider the factors affecting it.
