The total pressure in a flask containing air and ethanol at 257C is 878 mm Hg. The pressure of the air in the flask at 257C is 762 mm Hg. If the flask is immersed in a water bath at 400C, the total pressure is 980 mm Hg. The vapor pressure of ethanol at the new temperature is ? mm Hg.
At 257 C (which is 530 K), 878-762 or 116 mm Hg is the partial pressure of ethanol, and 762 mm Hg is the partial pressure of air.
At 400 C (673 K), the air's partial pressure increases to (673/530)*762 = 967.6 mm Hg. That would leave only 12.4 mm Hg for the partial pressure of ethanol if the total pressure is 980 mm Hg.
These numbers don't make sense. The partial pressure of ethanol should go up, not down, with temperature and I don't see how one could have a water bath at 400 C. Are sure you copied the numbers correctly?
The total pressure in a flask containing air and ethanol at 257C is 878 mm Hg. The pressure of the air in the flask at 257C is 762 mm Hg. If the flask is immersed in a water bath at 400C, the total pressure is 980 mm Hg. The vapor pressure of ethanol at the new temperature is mm Hg.
Hint: you will need to correct the pressure of air at the new temperature using the Gas Law: P1T1 = P2T2
he meant 25.70 and 40.00 degrees celsius
To find the vapor pressure of ethanol at the new temperature, you can use the ideal gas law. The ideal gas law states that the pressure, volume, and temperature of a gas are related by the equation:
PV = nRT
Where:
P = Pressure
V = Volume
n = Number of moles of the gas
R = Ideal gas constant (0.0821 L·atm/mol·K)
T = Temperature in Kelvin
In this case, the volume and number of moles of the gas remain constant, so we can rewrite the equation as:
P1/T1 = P2/T2
Where:
P1 = Initial pressure
T1 = Initial temperature
P2 = Final pressure
T2 = Final temperature
Now let's apply this to the given information:
Given:
P1 = 878 mm Hg (total pressure)
T1 = 25°C + 273.15 (conversion to Kelvin)
P2 = 980 mm Hg (total pressure)
T2 = 40°C + 273.15 (conversion to Kelvin)
Using the formula:
P1/T1 = P2/T2
Substituting the known values:
(878 mm Hg)/(25°C + 273.15 K) = (980 mm Hg)/(40°C + 273.15 K)
Now, let's solve this equation to find the unknown value, which is the vapor pressure of ethanol at the new temperature (P2):
P2 = P1 * (T2 / T1)
P2 = (878 mm Hg) * [(40°C + 273.15 K) / (25°C + 273.15 K)]
Now, we can calculate the value of P2 using the given numbers:
P2 = 878 * [(313.15 K) / (298.15 K)]
P2 = 922.32 mm Hg
Therefore, the vapor pressure of ethanol at the new temperature is approximately 922.32 mm Hg.