N2 was collected over water at 25 degrees C. The resulting pressure was 705 torr. The vapor pressure of water at 25 degrees C is 23.8 mm. What is the partial pressure of N2?
Dalton's Law--The total pressure is the sum of the partial pressures of each gas.
Ptotal = PN2 + PH2O
To find the partial pressure of N2, we need to subtract the vapor pressure of water from the total pressure measured.
1. Convert the vapor pressure of water from mm to torr:
We have: 23.8 mm
1 torr = 1 mm Hg
So, 23.8 mm = 23.8 torr
2. Subtract the vapor pressure of water from the total pressure:
Total pressure = 705 torr
Vapor pressure of water = 23.8 torr
Partial pressure of N2 = Total pressure - Vapor pressure of water
= 705 torr - 23.8 torr
= 681.2 torr
Therefore, the partial pressure of N2 is 681.2 torr.
To find the partial pressure of N2, we need to subtract the vapor pressure of water from the total pressure.
The given temperature is 25 degrees C, and the vapor pressure of water at that temperature is 23.8 mm. However, we need to convert the vapor pressure of water from mm to torr, as the total pressure is given in torr.
To convert mm to torr, we use the conversion factor: 1 mm = 0.001316 torr.
Converting the vapor pressure of water to torr:
23.8 mm * 0.001316 torr/mm = 0.03138 torr
Now, subtract the vapor pressure of water from the total pressure:
Partial pressure of N2 = Total pressure - Vapor pressure of water
Partial pressure of N2 = 705 torr - 0.03138 torr
Partial pressure of N2 = 704.96862 torr
Therefore, the partial pressure of N2 is approximately 704.97 torr.