Solubility of a gas in water Kinetic Molecular Theory

In summary, the solubility of a gas in water follows the kinetic molecular theory, where an increase in temperature results in higher kinetic energy and faster movement of gas molecules. This causes more molecules to escape from solution, decreasing the solubility. In contrast, a decrease in temperature leads to lower kinetic energy and slower movement of gas molecules, making it easier for them to stay dissolved in the water, resulting in an increase in solubility. This concept can be observed in everyday examples, such as the flat taste of soda or boiled water due to the escape of gas molecules.
  • #1
daNAV1GATOR
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Homework Statement



The solubility of a gas in water decreases as temperature
increases, and increases as temperature decreases. Using
the kinetic molecular theory, explain why this is so.

I would like an opinion please on my answer below. Is it a sufficient explanation?
THANKS! :smile:




The Attempt at a Solution



According to the Kinetic Molecular Theory, when you increase temperature, the
gas moleclues are moving faster causing the solubility to decrease because of
more collision between the particles. When the temperature decreases, the gas
molecules are not moving as fast, causing them to have a higher solubility.
 
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  • #2
How about this:

According to the kinetic molecular theory, increasing the temperature of water increases the kinetic energy of gas (and water) molecules, which then causes them to move faster. I learned in Physics that this is how evaporation works: Fast moving water molecules collide with other molecules near the surface. The molecules near the surface may then possesses enough kinetic energy to break free from the water. Now going back to the problem, when water is heated, gas molecules are given more energy causing them to move faster, which causes more molecules to leave the liquid. Thus, the solubility of a gas in water decreases because gas molecules will tend to be bumped out of the water. However, when the temperature is decreased, the kinetic energy of the molecules is decreased, creating lower-speed collisions. It is then easier for gas molecules to stay dissolved in the water.


**this is actually a Chemistry problem.**
 
  • #3
My side:

Increased temperature causes an increase in kinetic energy. The higher kinetic energy causes more motion in molecules which break intermolecular bonds and escape from solution.

This gas solubility relationship can be remembered if you think about what happens to a "soda pop" as it stands around for awhile at room temperature. The taste is very "flat" since more of the "tangy" carbon dioxide bubbles have escaped. Boiled water also tastes "flat" because all of the oxygen gas has been removed by heating.
 

FAQ: Solubility of a gas in water Kinetic Molecular Theory

1. How does temperature affect the solubility of a gas in water?

The solubility of a gas in water generally increases with decreasing temperature. This is because colder water molecules are closer together, creating more opportunities for gas molecules to interact and dissolve into the water.

2. What is the role of pressure in the solubility of a gas in water?

The solubility of a gas in water is directly proportional to the partial pressure of the gas above the water. This means that as pressure increases, more gas molecules are pushed into the water, increasing its solubility. This relationship is described by Henry's Law.

3. How does the type of gas affect its solubility in water?

The type of gas greatly affects its solubility in water. Some gases, such as carbon dioxide, are highly soluble in water, while others, such as nitrogen, are less soluble. This is due to differences in the intermolecular forces between the gas molecules and water molecules.

4. What is the Kinetic Molecular Theory and how does it relate to the solubility of a gas in water?

The Kinetic Molecular Theory states that all matter is made up of tiny particles in constant motion. This theory helps explain the solubility of gases in water by showing how gas molecules collide with water molecules and become trapped in the water's intermolecular spaces.

5. How can the solubility of a gas in water be increased?

The solubility of a gas in water can be increased by decreasing the temperature or increasing the pressure. Additionally, stirring or agitating the water can help increase the rate at which gas molecules dissolve into the water. Adding a surfactant, such as soap, can also increase the solubility of certain gases in water.

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