Answer:
a) 0.65
b) 0.342 atm
Explanation:
a) First, we need to know the molar mass of the compounds. By periodic table, the molar mass of the elements are:
C = 12 g/mol; Cl = 35.5 g/mol; H = 1 g/mol. So:
CCl4 = 12 + 4x35.5 = 154 g/mol
CHCl3 = 12 + 1 + 3x35.5 = 119.5 g/mol
They both have the same mass, so we can choose the basis of calculus as 100 g (you can choose any other basis, the result will be the same because the fraction will be the same!)
The number of moles is :
n = mass/molar mass
nCCl4 = 100/154 = 0.649 mol
nCHCl3 = 100/119.5 = 0.837 mol
So, the total number of moles is nt = nCCl4 + nCHCl3 = 1.486
Then, the molar fractions in the solution will be:
xCHCl3 = nCHCl3/nt = 0.837/1.486 = 0.56
xCCl4 = 1 - 0.56 = 0.44
By Dalton's Law
Pt = PCCl4*xCCl4 + PCHCl3*xCHCl3
Where Pt is the total pressure of the vapor, and PCCl4 and PCHCl3 are the vapor pressure of the compounds. So:
Pt = 0.44*0.354 + 0.56*0.526 = 0.451 atm
The molar fraction of the vapor will be:
yCHCl3 = (xCHCl3*PCHCl3)/Pt
yCHCl3 = (0.56*0.526)/0.451 = 0.65
b) When the vapor is condensed, the molar fraction of the vapor phase will be the molar fraction of the solution, so xCHCl3 = 0.65
P = molar fraction x vapor pressure
P = 0.65 x 0.526
P = 0.342 atm
The mole fraction of CHCl₃ in the vapor above the solution is equal to 0.65.
Given the following data:
Vapor pressure of CCl₄ = 0.354 atm.
Vapor pressure of CHCl₃ = 0.526 atm.
Scientific data:
Molar mass of CCl₄ = 154 g/mol.
Molar mass of CHCl₃ = 119.5 g/mol.
Next, we would determine the number of moles for each compound:
Note: Assume a mass of 100 grams.
Mathematically, the number of moles contained in a chemical compound is given by this formula:
[tex]Number \;of \;moles = \frac {mass}{molar\;mass}\\\\Number \;of \;moles = \frac {100}{154}[/tex]
Number of moles of CCl₄ = 0.649 mol.
For CHCl₃:
[tex]Number \;of \;moles = \frac {mass}{molar\;mass}\\\\Number \;of \;moles = \frac {100}{119.5}[/tex]
Number of moles of CHCl₃ = 0.837 mol.
The total number of moles = 0.649 + 0.837 = 1.486 mol.
For the mole fraction of CCl₄, we have:
[tex]M_f = \frac{0.649}{1.486} \\\\[/tex]
Mole fraction = 0.44.
For CHCl₃, we have:
Mole fraction = 1 - 0.44 = 0.56.
Next, we would determine the total pressure of the two compounds by applying Dalton's law:
Total pressure = 0.56 × 0.526 + 0.44 × 0.354
Total pressure = 0.451 atm.
Now, we can determine the mole fraction of CHCl₃ in the vapor above the solution:
[tex]Mole \;fraction = \frac{0.56 \times 0.526}{0.451}[/tex]
Mole fraction = 0.65.
Vp = molar fraction × vapor pressure
Vp = 0.65 × 0.526
Vp = 0.342 atm.
Read more on pressure here: https://brainly.com/question/24827501
