[premedman]

a. If a sample of vapor is found to have a composition of equal parts benzene and toluene, what is the composition of the boiling liqiod that produced this vapor?

b. Explain the meaning of the horizontal line AB in the picture I submitted.

c. What physical transformation does the line DE represent in the picture I submitted.

d. In reference to the picture i submitted, what is the approximate boiking point of a liquid that is 20% benzene and 8% toluene?

e. Under what conditions can a good reparation be achievedby simple distillation

f. Calculate the mole fraction of each component in the oslution if you mix 8.4 g if cyclohexane and 9.2 g of toluene.

g. Assuming that thi is an ideal mixture that follows Raoult's law, calculate the partial vapor presure of cyclohexane in the mixture at 50*C

h. Estimate to the nearest degree the boiling point temperature of this solution.

i.Explain why the boiling point of your cyclohexane:Toluene mixture rose slowly throughout your simple distillation procedure.

[premedman]

Please read forum rules.

You have to show your attempts at solving the question to receive help. This is a forum policy.

Uploaded with ImageShack.us
I have been working on this this for the past 3 days. How am I supposed to show that I have "attempted" this. Shall I scan a graph I sketched?

I have figured out this so far:


1a. The precent composition will have 51% benzene and 49% toluene.
1b.

2a. This line represents the conversion from a liquid to a gas.
2b. The physical transformation from D to E results in a more concentration benzene.

3.

4. A difference in boiling points > 30°C

5a

For the past 3 days, I have not been able to work out the rest, and even that, I barely worked out the ones above. Please, do not assume I want to cheat my way to a good grade. I pride myself in my worth ethic and simply want help from members of this forum.

[Borek]

Posting a plot you sketched would be perfect.

Numbering of the questions and answers you posted is different, but I hope they are in the same order.

If so, your first answer is already wrong. If the vapor is 50/50, composition of boiling liquid is not close to that, it is quite different. And it contains more toluene than benzene.

[fledarmus]

For question 1, look at the chart you posted. The lower curve is the composition of the liquid when it begins to boil. The upper curve is the composition of the vapor when it begins to condense.

So for your distillation, what you want to know is what the composition of the liquid is, when the composition of the condensing vapor is 50/50. Find the point that represents a 50/50 composition on the upper curve, determine the temperature at that point, and find the point where the lower curve crosses that same temperature. The composition at that point will be the composition of a boiling liquid required to give a 50/50 composition of vapor.

[premedman]

Thanks, I figured it all out. Pulled an All-Nighter but came up with the answers, slowly.