Physical Principles II
CEBU CITY
Chemical Engineering Department
Name: Juphil Lamanilao Date: October 15, 2009
Course & Yr: BSChE-4
I.TITLE: Distribution of a Solute between Immiscible Solvents
II.OBJECTIVE:
• To determine the distribution coefficient K.
III.APPARATUS:
(3) 100-ml separatory funnels, (3) 100-ml Erlenmeyer flasks, 100ml volumetric
flask, 25-ml & 10-ml pipette, 1N CH3COOH, glacial CH3COOH, CCl4, ether, 0.5N
NaOH, 0.01N NaOH
IV.SKETCH:
Distribution of a Solute between Immiscible Solvents 1

Physical Principles II
V.TABULATED DATA & RESULTS:
Concentration Distributio
Solution Volume of Volume of Volume of n
H2O added NaOH used of HAc (ml)
Sample Coefficient
UPPER LOWER UPPER LOWER UPPER LOWER UPPER LOWER K
0.5N HAc
+ diethyl 2 ml 2 ml 75 ml 75 ml 1.3 ml 2.8 ml 0.325 0.70 1.3
ether
1N HAc +
diethyl 2 ml 2 ml 50 ml 50 ml 2.5 ml 4.2 ml 0.625 1.05 1.8
ether
2N HAc
+ diethyl 2 ml 2 ml 25 ml 25 ml 5.5 ml 12 ml 1.375 3.0 2.2
ether
VI.SAMPLE COMPUTATIONS:
UPPER: LOWER:
a. 2x = 1.3(0.5) = 0.325 a. 2x = 2.8(0.5) = 0.70
b. 2x = 2.5(0.5) = 0.625 b. 2x = 4.2(0.5) = 1.05
c. 2x = 5.5(0.5) = 1.375 c. 2x = 12(0.5) = 3.0
Distribution of a Solute between Immiscible Solvents 2

Physical Principles II
VII.DATA ANALYSIS:
The addition of an excess of a liquid to a mixture of two immiscible liquids will
results in the additive being distributed between two phases. That is, for every mixture
of CH3COOH and diethyl ether with corresponding increasing concentrations at the
same time the distribution coefficient (K) also increases relatively. In addition, more
volume was consumed on the lower portion of the mixture as the dissolved substance
between the two given immiscible solvents distribute itself to a definite equilibrium. If
the additive is added at less than saturating amounts, it will also become distributed
liquids at a defined concentration ratio.
VIII.APPLICATION TO ChE:
The influence of solvent-solvent interactions on the solubility of drugs is a critical
topic of which future chemists need to have a thorough grasp. Also applied to
chromatography where the stationary phases are water molecules bound to a cellulose
matrix. It is a critical parameter for purification using ozone melting.
IX.CONCLUSION:
In the experiment, a solute is distributed between two phases in a dynamic
(heterogeneous) equilibrium. If a substance is added to a mixture which is soluble to a
greater or lesser extent in both immiscible liquids, on shaking and then allowing the
mixture to settle, the concentrations in each layer become constant. However, there is
continual interchange of solute between the liquid layers via the interface. If more of the
substance is added to the system, the solute will distribute itself between the immiscible
liquids so that the ratio of the solute concentrations remains the same at constant
temperature independently of the total quantity of a solute in the same molecular state.
When the molecular weight of a solute is different in the two solvents, the ratio of the
concentrations in the two phases is not constant, and in contrary, if the ratio varies
considerably with concentration, it may be deduced that the molecular weight of the
solute is not identical in the two solvents.
Distribution of a Solute between Immiscible Solvents 3