Final answer:
To calculate the partial pressure of dry air from the total pressure of wet air at 765.0 mmHg, subtract the pressure of water vapor (47 mmHg) from the total pressure resulting in 718.0 mmHg for the dry air.
Step-by-step explanation:
The question asks for the partial pressure of dry air when the total pressure of wet air is 765.0 mmHg at 25 degrees Celsius. To find this, we must account for the partial pressure of water vapor in the air, which at this temperature is typically 47 mmHg. Therefore, we subtract the water vapor pressure from the total pressure to obtain the partial pressure of the dry air.
To calculate:
Partial Pressure of Dry Air = Total Pressure of Wet Air - Pressure of Water Vapor
= 765.0 mmHg - 47 mmHg
= 718.0 mmHg
Therefore, the partial pressure of dry air is 718.0 mmHg.