The vapor pressure of chloroform is 173.11 mm Hg at 25 °C. A nonvolatile, nonelectrolyte that dissolves in chloroform is aspirin. Calculate the vapor pressure of the solution at 25 °C when 9.322 grams of aspirin, C9H8O4 (180.1 g/mol), are dissolved in 263.4 grams of chloroform. chloroform = CHCl3 = 119.40 g/mol. VP(solution) = mm Hg

VP (solution) = 171.56 mmHg

Explanation:

Vapor pressure of pure solvent(P°) - Vapor pressure of solution (P') = P° . Xm

Let's replace the data:

173.11 mmHg - P' = 173.11 mmHg . Xm

Let's determine the Xm (mole fraction for solute)

Mole fraction for solute = Moles of solute / Total moles

Total moles = Moles of solute + moles of solvent.

Let's determine the moles

Moles of solvent → 623.4 g / 119.4 g/mol = 5.22 moles

Moles of solute → 9.322 g / 180.1 g/mol = 0.052 moles

Total moles = 0.052 + 5.22 = 5.272 moles

Xm = 0.052 moles / 5.272 moles = 0.009 → 9/1000

173.11 mmHg - P' = 173.11 mmHg . 9/1000

P' = - (173.11 mmHg . 9/1000 - 173.11 mmHg)

P' = 171.56 mmHg

The vapor pressure of the solution is 169.25 mm Hg

Explanation:

Step 1: Data given

Vapor pressure of pure chloroform at 25 °C = 173.11 mm Hg

Mass of aspirin = 9.322 grams

Molar mass of aspirin = 180.1 g/mol

Mass of chloroform = 263.4 grams

Molar mass chloroform = 119.40 g/mol

Step 2: Calculate moles of aspirin

Moles Aspirin = mass aspirin / molar mass aspirin

Moles aspirin = 9.322 grams / 180.1 g/mol

Moles aspirin = 0.05176 moles

Step 3: Calculate moles of chloroform

Moles chloroform = 263.4 grams / 119.40 g/mol

Moles chloroform = 2.206 moles

Step 4: Calculate mol fraction of chloroform

Mol fraction chloroform = moles chloroform / total moles

Mol fraction chloroform = 2.206 moles / (0.05176 + 2.206 )

Mol fraction chloroform = 0.9777

Mol fraction aspirin = 1 - 0.9777 = 0.0223

Step 5: Calculate the vapor pressure of the solution

Vapor pressure solution = Mol fraction chloroform * vapor pressure chloroform

Vapor pressure solution = 0.9777 * 173.11 mm Hg

Vapor pressure solution = 169.25 mm Hg

The vapor pressure of the solution is 169.25 mm Hg

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.