In an indoor swimming pool the air above the pool of water e

In an indoor swimming pool, the air above the pool of water exists with water vapor. Assuming the system is composed of the air, water vapor and liquid water in the pool: Identify the phases. Identify the substances.

Solution

a. The Phases:

1.The phase inside the pool is liquid.

2. The phase of the layer just above the pool surface is water vapour with a relative humidity of close to 1.

3. As we move farther away from the surface of water, the water vapour content in the air goes down and the value of relative humidity goes towards zero.

b. The substances:

1. Inside the water of the pool, the substance is mainly H₂ O.

2. Just above the water surface, the substance is mainly air along with water vapour.

3. As we move farther away from the surface of water, the water vapour content in the air goes down and we find the air composition close to:  78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases.