Answer:
a. Molarity= 
b. Molality= 
Explanation:
Hello,
In this case, given the information about the aniline, whose molar mass is 93g/mol, one could assume the volume of the solution is just 200 mL (0.200 L) as no volume change is observed when mixing, therefore, the molarity results:

Moreover, the molality:

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Explanation:
Transfer of mass A into stagnant film B depends on the availability of driving force.
Whereas driving force is the pressure difference at the surface of A and the bulk.
As, 

Therefore, putting the given values into the above formula as follows.

= 
= 0.132 
Thus, we can conclude that the flux of A from a surface into a mixture of A and B is 0.132 
Answer:
the anwser isn't in the choices
Explanation:
H=MC(change of temp.)
M=mass of water=250g
C=specific heat of water = 4.186 j/g
change in temperature is 121-40= 81
H= 250x4.186x81=84766.5J
According to Raoult's low:
We will use this formula: Vp(Solution) = mole fraction of solvent * Vp(solvent)
∴ mole fraction of solvent = Vp(Solu) / Vp (Solv)
when we have Vp(solu) = 25.7 torr & Vp(solv) = 31.8 torr
So by substitution:
∴ mole fraction of solvent = 25.7 / 31.8 =0.808
when we assume the moles of solute NaCl = X
and according to the mole fraction of solvent formula:
mole fraction of solvent = moles of solvent / (moles of solvent + moles of solute)
by substitute:
∴ 0.808 = 0.115 / (0.115 + X)
So X (the no.of moles of NaCl) = 0.027 m