Answer:
The Avogadro's number is 
Explanation:
From the question we are told that
The edge length is 
The density of the metal is 
The molar mass of Ba is 
Generally the volume of a unit cell is
substituting value
![V = [5.02 *10^{-10}]^3](https://tex.z-dn.net/?f=V%20%3D%20%20%5B5.02%20%2A10%5E%7B-10%7D%5D%5E3)
From the question we are told that 68% of the unit cell is occupied by Ba atoms and that the structure is a metal which implies that the crystalline structure will be (BCC),
The volume of barium atom is
substituting value
The Molar mass of barium is mathematically represented as
Where 
is the Avogadro's number
So
substituting value
Raoult's law is stated as<span> the partial </span>vapor pressure<span> of each component in the </span> mixture<span> of ideal liquids is equal to the vapor pressure of the pure component multiplied by its </span>mole fraction<span> in the mixture. Mathematically, it is expressed as
P = Xi Pi
where P= vapor pressure of solution
Xi = mole fraction of i component
Pi = vapor pressure of pure i component.
In present case, P1 = 0.459 atm and n1 = number of mole of ethanol = 0.090
n2 = number of mole of </span><span> naphthalene = 0.01
</span>∴ Mole fraction of ethanol =
=
= 0.9
Thus, vapor pressure of solution = 0.9 X 0.459 = 0.4131 atm.
Answer: <span>The vapor pressure of pure ethanol at 60 °c is 0.459 atm. Raoult's law predicts that a solution prepared by dissolving 10.0 mmol naphthalene (nonvolatile) in 90.0 mmol ethanol will have a vapor pressure of
0.4131 atm.</span>
It is an example of a molecule
