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 450C, the
total pressure is 980 mm Hg. The vapor pressure of ethanol at the new temperature is _____ mm Hg.

I really don't know what to do..i drew a picture but theres just so much info i cant seem to focus on what i need to find.

Hmmmm. A water bath at 450C???????

Neglecting that crazy temperature's effect on water,

the pressure of of the ethanol goes up proportionally as does the air.

The total pressure increased 980/878. Each partial pressure increased by the same factor.

new ethanol pressure= 980/878 * (878-257)

***** 25.7, 25.7, 45.0

sryy

To solve this problem, you'll need to understand the concept of vapor pressure and how it changes with temperature.

Vapor pressure is the pressure exerted by a vapor in equilibrium with its liquid phase at a given temperature. In this case, we're looking for the vapor pressure of ethanol at 45°C.

We're given the total pressure in the flask at two different temperatures, as well as the pressure of the air at the initial temperature. This information allows us to determine the pressure contributed by the ethanol vapor at the initial temperature.

To find the vapor pressure of ethanol at the new temperature, we need to use the Clausius-Clapeyron equation, which relates the vapor pressure of a substance at two different temperatures:

ln(P2/P1) = (-ΔHvap/R) * (1/T2 - 1/T1)

Where:
- P2 is the vapor pressure at the new temperature (45°C)
- P1 is the vapor pressure at the initial temperature (25.7°C)
- ΔHvap is the heat of vaporization of the substance (constant for a given substance)
- R is the ideal gas constant (8.314 J/mol·K)
- T2 is the new temperature in Kelvin (45 + 273.15)
- T1 is the initial temperature in Kelvin (25.7 + 273.15)

However, since we don't know ΔHvap for ethanol, we need to use an alternate method to find the vapor pressure.

We can use Dalton's Law of partial pressures, which states that the total pressure exerted by a mixture of non-reacting gases is equal to the sum of the partial pressures of the individual gases:

Ptotal = Pethanol + Pair

Therefore, to find the vapor pressure of ethanol at the new temperature, we can subtract the partial pressure of air at the new temperature from the total pressure at the new temperature:

Pethanol = Ptotal - Pair

Substituting the given values, we get:

Pethanol = 980 mmHg - 762 mmHg

Therefore, the vapor pressure of ethanol at the new temperature is 218 mmHg.