A Relative humidity is the ratio of the partial pressure of...

A Relative humidity is the ratio of the partial pressure of water in air at a given temperature to the vapor pressure of water at that temperature. Calculate the mass of water per liter of air under the following conditions. (a) at $20^{\circ} \mathrm{C}$ and $45 \%$ relative humidity (b) at $0^{\circ} \mathrm{C}$ and $95 \%$ relative humidity Under which circumstances is the mass of $\mathrm{H}_{2} \mathrm{O}$ per liter greater? (See Appendix G for the vapor pressure of water.)

A Relative humidity is the ratio of the partial pressure of water in air at a given temperature to the vapor pressure of water at that temperature. Calculate the mass of water per liter of air under the following conditions.
(a) at $20^{\circ} \mathrm{C}$ and $45 \%$ relative humidity
(b) at $0^{\circ} \mathrm{C}$ and $95 \%$ relative humidity Under which circumstances is the mass of $\mathrm{H}_{2} \mathrm{O}$ per liter greater? (See Appendix G for the vapor pressure of water.)

Key Concepts

Relative Humidity

Relative humidity is the ratio of the actual partial pressure of water vapor present in the air to the saturation vapor pressure at a given temperature. It is typically expressed as a percentage, indicating how close the air is to being saturated with water vapor. This concept is crucial because it provides a measure of the moisture content relative to what the air can hold before condensation occurs.

Saturation Vapor Pressure

Saturation vapor pressure is the pressure at which water vapor is in equilibrium with its liquid phase at a specific temperature. It represents the maximum amount of water vapor that air can hold before condensation begins. Understanding saturation vapor pressure is important to determine how much moisture the air can accommodate, which directly affects calculations involving relative humidity and water content.

Ideal Gas Law

The ideal gas law relates the pressure, volume, temperature, and number of moles of a gas. It is used in calculations involving the water vapor in air to convert between the measured pressure and the number of moles, which can then be used to determine the mass of water vapor present. This principle is essential in estimating the density or mass of water in a given volume of air.

Conversion of Moles to Mass

Once the number of moles of water vapor is determined using the ideal gas law, converting these moles to mass involves multiplying by the molar mass of water. This step is essential for practical calculations where the final result is expressed as the mass of water per unit volume of air. Understanding how to perform this conversion is key to solving problems related to humidity and water content in the atmosphere.

Transcript

Please give Ace some feedback