762 + vp ethanol = total pressure.
Dalton's Law of partial pressures.
The total pressure in a flask containing air and ethanol at 257C is 882 mm Hg. If the pressure of the air in the flask is 762 mm Hg, the vapor pressure of ethanol is ?mm Hg.
882-762=120mm Hg
To find the vapor pressure of ethanol in this scenario, we can use Dalton's Law of partial pressures, which states that the total pressure of a mixture of gases is equal to the sum of the partial pressures of each individual gas.
In this case, the total pressure is given as 882 mm Hg, and the pressure of air is 762 mm Hg. We need to find the vapor pressure of ethanol.
Using Dalton's Law, we can set up the equation:
Total pressure = Pressure of air + Vapor pressure of ethanol
882 mm Hg = 762 mm Hg + Vapor pressure of ethanol
To isolate the vapor pressure of ethanol, we can rearrange the equation:
Vapor pressure of ethanol = Total pressure - Pressure of air
Substituting the given values:
Vapor pressure of ethanol = 882 mm Hg - 762 mm Hg
Vapor pressure of ethanol = 120 mm Hg
Therefore, the vapor pressure of ethanol in the flask is 120 mm Hg.