Question

110 110 Vapor C100 100 90 Liquid 80 80 Cycl 0% Tol. 100% 100% Cycl. 0% Tol. 60 40 60 80 20 40 Mole percent cyclohexane Mole percent toluene 1. Use the phase diagram above to answer the following. Show work on the phase diagram. Starting with a solution that is 80.0 % toluene at 80°C a. At what point does this solution start to boil? b. What is the composition of this vapor? How many plates (steps of condensation and redistillation) are necessary to achieve a vapor that is 95% cyclohexane? C. Temperature. C 90

Answer 1

This is a temperature composition phase diagram which tells us information about the binary mixture information under different temperature and concentration

Let's solve this questions one by one.

01.

At what point the 80% tolune will start to boil

For this we need to draw a line paralllel to x axis and going through liquid curve as follows

110 110 Vapor TI 100 100 Temperature, 90 Liquid 80 100% Cycl. B0 60 40 20 Cycl. 0%

As we can see from the image the temperature at which the liquid will boil is nearly 102 °C

Now the second question

question 2.

what will be the composition of vapor at this point

For this we draw a line parallel to the x axis passing through boiling point in liquid line and extend it at x axis

We can see a line passing through t1 in above graph

It intersencts x axis at nealy 50% point

So the vapor has composition 50% tolune and 50% cylohexane

question c.

For this we need to start drawing steps as shown in the image below

Each step represent one condensation and one distillation

110 110 Vapor 100 100 Temperature, C 90 90 Liquid 100% Cycl. 0% Tol. 80 60 40 60 Cycl. 0% Tol. 100% 20 40 - Mole percent cyclohexane Mole percent toluene--

As you can see 3 steps are required from given point to reach 95% cyclohexane

So the answer is 3 plates

I hope this helps if you have any query or want more detailed explanation feel free to ask in the comments section below.