Answer : The correct option is, (b) 0.087
Explanation :
The formula used for relative saturation is:
![\text{Relative saturation}=\frac{P_A}{P_A^o}](https://tex.z-dn.net/?f=%5Ctext%7BRelative%20saturation%7D%3D%5Cfrac%7BP_A%7D%7BP_A%5Eo%7D)
where,
= partial pressure of ethyl acetate
= vapor pressure of ethyl acetate
Given:
Relative saturation = 50 % = 0.5
Vapor pressure of ethyl acetate = 16 kPa
Now put all the given values in the above formula, we get:
![0.5=\frac{P_A}{16kPa}](https://tex.z-dn.net/?f=0.5%3D%5Cfrac%7BP_A%7D%7B16kPa%7D)
![P_A=8kPa](https://tex.z-dn.net/?f=P_A%3D8kPa)
Now we have to calculate the molar saturation.
The formula used for molar saturation is:
![\text{Molar saturation}=\frac{P_{vapor}}{P_{\text{vapor free}}}](https://tex.z-dn.net/?f=%5Ctext%7BMolar%20saturation%7D%3D%5Cfrac%7BP_%7Bvapor%7D%7D%7BP_%7B%5Ctext%7Bvapor%20free%7D%7D%7D)
and,
P(vapor free) = Total pressure - Vapor pressure
P(vapor) =
= 8 kPa
So,
P(vapor free) = 100 kPa - 8 kPa = 92 kPa
The molar saturation will be:
![\text{Molar saturation}=\frac{P_{vapor}}{P_{\text{vapor free}}}](https://tex.z-dn.net/?f=%5Ctext%7BMolar%20saturation%7D%3D%5Cfrac%7BP_%7Bvapor%7D%7D%7BP_%7B%5Ctext%7Bvapor%20free%7D%7D%7D)
![\text{Molar saturation}=\frac{8kPa}{92kPa}=0.087](https://tex.z-dn.net/?f=%5Ctext%7BMolar%20saturation%7D%3D%5Cfrac%7B8kPa%7D%7B92kPa%7D%3D0.087)
Therefore, the molar saturation is 0.087