Problem 79 - Introductory Chemistry Atoms First

Question

Give an example of a gas dissolved in another gas. Is this mixture homogeneous?

Step-by-Step Solution

Answer

One common example of a gas dissolved in another gas is the air we breathe, which is primarily composed of nitrogen gas (\(78\%\)) and oxygen gas (\(21\%\)), with traces of other gases such as argon, carbon dioxide, and some other gases. This mixture of gases is considered homogeneous, as the components are evenly distributed throughout the mixture.

Step 1: Example of a gas dissolved in another gas

One common example of a gas dissolved in another gas is the air we breathe. Air is primarily composed of nitrogen gas (\(78\%\)) and oxygen gas (\(21\%\)), with traces of other gases such as argon, carbon dioxide, and some other gases.

Step 2: Homogeneous Mixture

Now let's analyze whether this mixture of gases is homogeneous or not. In a homogeneous mixture, the components are evenly distributed throughout the mixture. In the case of the air we breathe, the nitrogen, oxygen, and the other trace gases are uniformly combined, so we can say that we breathe a homogeneous mixture of gases.

Key Concepts

Gas Solutions

Gas solutions occur when one gas is dissolved in another gas. A common example is the air around us. Here, nitrogen acts as the primary solvent, and oxygen, along with other trace gases, are solutes. In this context, the solution forms because gases can mix evenly at the molecular level. This nature of gases allows them to diffuse and interact freely, creating a uniform mixture.

• Gas solutions are vital in various natural and industrial processes.
• The ability of gases to mix spontaneously improves their usage in different applications, such as in breathing or combustion.

Understanding gas solutions requires recognizing how molecules of one gas move within and among the molecules of another gas without separation.

Homogeneous Mixtures

Homogeneous mixtures are uniform in composition, meaning they are the same throughout. In the context of gases, air is a classic example. Even though it contains multiple gases, they are so finely mixed that you cannot identify individual gases with the naked eye. This uniformity means:

• No visible boundaries exist between different components.
• Each sample taken from the mixture will be the same as any other.

Homogeneous mixtures are essential in daily life. They ensure consistency in products and processes, making them predictable and reliable.

Atmospheric Composition

The atmosphere is a blend of gases that surround our planet, with nitrogen and oxygen making up most of it. The composition is roughly:

• Nitrogen: 78%
• Oxygen: 21%
• Argon: 0.93%
• Carbon dioxide: 0.04%

Other trace gases also exist in smaller quantities. This composition supports life by providing essential gases for respiration, photosynthesis, and climate regulation.
The consistency of atmospheric composition worldwide is a testament to the earth's dynamic systems that mix and maintain gas levels, creating a robust environment for various life forms to thrive.