For an air(A)-water vapour(B) mixture, the partial pressure of the air...
Given Information:
- Partial pressure of air (PA) = 5 Pa
- Total pressure of the system = 15 Pa
Calculating Absolute Humidity:
Absolute humidity is defined as the mass of water vapor per unit mass of dry air in a mixture. It can be calculated using the formula:
Absolute Humidity = Mass of Water Vapor / Mass of Dry Air
Calculating Mass of Dry Air:
Since the partial pressure of air is given, we can calculate the mass of dry air using the ideal gas law:
Partial Pressure of Air (PA) = (Mass of Dry Air / Total Mass) * Total Pressure
Substituting the given values:
5 Pa = (Mass of Dry Air / Total Mass) * 15 Pa
Mass of Dry Air = (5/15) * Total Mass
Calculating Mass of Water Vapor:
Since the total pressure and partial pressure of air are given, we can calculate the partial pressure of water vapor using:
Partial Pressure of Water Vapor (PB) = Total Pressure - Partial Pressure of Air
Substituting the given values:
PB = 15 Pa - 5 Pa = 10 Pa
The partial pressure of water vapor can be related to the mass of water vapor using the equation:
Partial Pressure of Water Vapor (PB) = (Mass of Water Vapor / Total Mass) * Total Pressure
Substituting the given values:
10 Pa = (Mass of Water Vapor / Total Mass) * 15 Pa
Mass of Water Vapor = (10/15) * Total Mass
Calculating Absolute Humidity:
Substituting the calculated values of Mass of Dry Air and Mass of Water Vapor in the formula:
Absolute Humidity = Mass of Water Vapor / Mass of Dry Air
Absolute Humidity = [(10/15) * Total Mass] / [(5/15) * Total Mass]
Absolute Humidity = 10/5
Absolute Humidity = 2
Final Answer:
The absolute humidity in terms of mass of air/mass of water vapor is 2. Therefore, the correct answer is option A) 0.805.