Question

Using the phase diagram table in the Elementary Principles of Chemical Processes book.

Ten kilograms of 20% MlBK-30% water-50% acetone mixture is added to 20 Kg of 5% MIBK-65% water-30% acetone solution. How many phases will be formed in the final mixture? If one phase, what are the mass and composition of the phase? If two phases, what are the mass and composition of each phase?

Answer 1

In the given mixture the final composition is

Total amount = 10+ 20 = 30 Kg

MIBK = 20% X 10Kg + 5% X 20 Kg = 2+ 1 = 3 Kg therefore % in final = 10%

Water = 30% X 10Kg + 65% X 20 Kg = 3 +13 = 16 Kg Therefore % in final = 16 x 100 / 30 = 53.33%

acetone = 50% X 10Kg + 30% X 20 Kg = 5 + 6 = 11 Kg therefore % in final = 36.67 %

Now looking at the diagram mentioned in the book ( i am using the same from the book mentioned by you,Elementary Principles of Chemical Processes book).

6 Multiphase Systems Acetone the desired point Region A Region B MIBK H20 Figure 6.6-1 Triangular phase diagram for water-acetone-methyl isobutyl ke- tone (composition in wt%) at 25°C (From D. F. Othmer, R. E. White, and E. Trueger, Ind. Eng. Chem. 33 1240, 1941)

The point is marked with blue line, it is in region B

1) Phases = two

2) The mass composition is already calculated above