D is the answer I believe.
Answer:
30.4 torr
Explanation:
We have all the information which is required to solve this question ( more than we even need as the molecular weight)
Ptotal = Ptoluene + Pbenzene
Ptotal = Xtoluene Pºtoluene + XbenzenePºbenzene
The mole fraction is given by the formula:
X =number of moles / total number of moles
Xtoluene = 8.53 / (2.15+8.53) = 0.80
Xbenzene = 2.15 / 10.68 = 0.20
⇒Ptotal = 0.80 x 14torr + 0.20 x 96 torr = 30.4 torr
