Henry's Law states that the solubility of a gas in a liquid is directly proportional to the partial pressure of the gas above the liquid. This means that as the pressure of the gas increases, the amount of gas that dissolves in the liquid also increases....
The mathematical expression for Henry's Law is:
C = kP
Where:
- C is the concentration of the dissolved gas
- k is the Henry's Law constant, which is a proportionality constant specific to the gas and the solvent
- P is the partial pressure of the gas
Applying Henry's Law to the Given Problem
In this problem, we are given the following information:
- The solubility of the gas at 4.0 atm of pressure is 0.85 g/L.
- We want to find the solubility of the gas at 1.0 atm of pressure.
To solve this problem, we can use the following steps:
- Find the Henry's Law constant (k):
We can rearrange the Henry's Law equation to solve for k:
k = C/P
Substituting the given values, we get:
k = 0.85 g/L / 4.0 atm = 0.2125 g/(L*atm)
- Calculate the solubility at 1.0 atm:
Now that we know k, we can use the Henry's Law equation to calculate the solubility at 1.0 atm:
C = kP = (0.2125 g/(L*atm)) * (1.0 atm) = 0.2125 g/L
Therefore, the solubility of the gas at 1.0 atm of pressure is 0.2125 g/L.
Factors Affecting Gas Solubility
The solubility of a gas in a liquid is influenced by several factors, in addition to pressure:
- Temperature: Generally, the solubility of gases decreases as temperature increases. This is because the kinetic energy of the gas molecules increases at higher temperatures, making them more likely to escape from the liquid phase.
- Nature of the Gas: The type of gas plays a significant role in its solubility. For example, gases that are more polar or have stronger intermolecular forces are more likely to dissolve in polar solvents like water.
- Nature of the Solvent: The solvent also influences gas solubility. For instance, non-polar solvents like hexane tend to dissolve non-polar gases better than polar solvents like water.
Applications of Henry's Law
Henry's Law has numerous applications in various fields, including:
- Environmental Science: To understand the dissolution of gases like carbon dioxide and oxygen in water bodies, impacting aquatic life and climate change.
- Chemical Engineering: In designing and optimizing processes involving gas absorption and desorption, such as in industrial processes.
- Medicine: In understanding the transport of gases like oxygen and carbon dioxide in the bloodstream.
- Diving: To calculate the amount of nitrogen that dissolves in the body at different depths, preventing decompression sickness (the bends).
Conclusion
Henry's Law provides a fundamental understanding of the relationship between pressure and gas solubility. This law has wide-ranging applications in various fields, enabling us to predict and control the behavior of gases in liquid solutions. By applying Henry's Law, we can analyze and understand various natural and industrial processes involving gas dissolution.