A solution contains naphthalene(C10H8) dissolved in hexane (C6H14) at a concentration of 14.52 % naphthalene by mass.Calculate the vapor pressure at 25 degrees C of hexane above the solution. The vapor pressure of pure hexane at 25 degrees C is 151 .

139.9

Psolution = Xhexane*Pohexane

14.52% by mass = 14.52g naphthalene dissolved in 14.52 g naphthalene+85.48 g hexane.
Convert 14.52 g naphthalene to moles.
Convert 85.48 g hexane to moles.
mole fraction hexane = moles hexane/total moles.

To calculate the vapor pressure of hexane above the solution, we need to use Raoult's law. According to Raoult's law, the vapor pressure of a component in a solution is directly proportional to its mole fraction in the solution.

First, we need to calculate the mole fraction of hexane (C6H14) in the solution. Let's assume we have 100 grams of the solution. Since the solution is 14.52% naphthalene by mass, we have:

Mass of naphthalene = 14.52% of 100 grams = 14.52 grams
Mass of hexane = 100 grams - 14.52 grams = 85.48 grams

Next, we need to convert the masses of naphthalene and hexane to moles. We can do this by dividing the masses by their respective molar masses:

Molar mass of naphthalene (C10H8) = 10 * (12.01 g/mol) + 8 * (1.008 g/mol) = 128.18 g/mol
Molar mass of hexane (C6H14) = 6 * (12.01 g/mol) + 14 * (1.008 g/mol) = 86.18 g/mol

Moles of naphthalene = 14.52 grams / 128.18 g/mol = 0.1132 mol
Moles of hexane = 85.48 grams / 86.18 g/mol = 0.9917 mol

Now, we can calculate the mole fraction of hexane:

Mole fraction of hexane = Moles of hexane / (Moles of naphthalene + Moles of hexane)
= 0.9917 mol / (0.1132 mol + 0.9917 mol)
= 0.9917 / 1.1049
= 0.8957

Finally, we can calculate the vapor pressure of hexane above the solution using Raoult's law. The vapor pressure of pure hexane at 25 degrees C is 151 mmHg:

Vapor pressure of hexane above the solution = Mole fraction of hexane * Vapor pressure of pure hexane
= 0.8957 * 151 mmHg
= 135.66 mmHg

Therefore, the vapor pressure of hexane above the solution at 25 degrees C is approximately 135.66 mmHg.

To calculate the vapor pressure of hexane above the solution, we need to use Raoult's Law, which states that the vapor pressure of a component in a solution is directly proportional to the mole fraction of that component in the solution.

First, let's calculate the mole fraction of hexane in the solution.

Mole fraction of hexane (X_hexane) = moles of hexane / total moles in the solution

Since we know the percentage of naphthalene by mass in the solution, we can calculate the mass of hexane and naphthalene.

Mass of naphthalene = (14.52 / 100) * mass of solution

Mass of hexane = mass of solution - mass of naphthalene

Next, we need to convert the mass of hexane and naphthalene to moles.

Moles of naphthalene = Mass of naphthalene / molar mass of naphthalene

Moles of hexane = Mass of hexane / molar mass of hexane

Now, we can calculate the total moles in the solution.

Total moles in the solution = Moles of naphthalene + Moles of hexane

Finally, we can calculate the mole fraction of hexane.

X_hexane = Moles of hexane / Total moles in the solution

With the mole fraction of hexane, we can calculate the vapor pressure of hexane above the solution using Raoult's Law.

Vapor pressure of hexane above the solution = X_hexane * vapor pressure of pure hexane

Now, let's plug in the provided values and calculate.

Given:
Concentration of naphthalene = 14.52%
Vapor pressure of pure hexane = 151 mmHg

Step 1: Calculate the mass of naphthalene and hexane.
Mass of naphthalene = (14.52 / 100) * mass of solution
Mass of hexane = mass of solution - mass of naphthalene

Step 2: Calculate the moles of naphthalene and hexane.
Moles of naphthalene = Mass of naphthalene / molar mass of naphthalene
Moles of hexane = Mass of hexane / molar mass of hexane

Step 3: Calculate the total moles in the solution.
Total moles in the solution = Moles of naphthalene + Moles of hexane

Step 4: Calculate the mole fraction of hexane.
X_hexane = Moles of hexane / Total moles in the solution

Step 5: Calculate the vapor pressure of hexane above the solution using Raoult's Law.
Vapor pressure of hexane above the solution = X_hexane * vapor pressure of pure hexane

Now, you can substitute the given values and solve for the vapor pressure of hexane above the solution at 25 degrees Celsius.