Determination the critical solution temperature of phenol –water system.

 Experiment

DETERMINATION OF CRITICAL SOLUTION TEMPERATURE OF PHENOL –WATER SYSTEM

Aim:

To determine the critical solution temperature of phenol –water system.

Requirements:

Chemicals:

• Phenol in liquid state.

• Distilled water.

 Apparatus:

• Analytical balance

• Hard glass tube

• Thermometer

• Beakers

• Stirrer

• Water-bath

Principle:

• Critical solution temperature is defined as the temperature at which tow conjugate solution merge into one another to form one layer. This is characterized of a particular system.

• When small quantity of phenol is mixed with water and the mixture is shaken. Phenol dissolves forming a single layer and adding layer quantities of phenol however two kinds of composition of liquid are formed. The lower layer consists of small amount of water dissolves in phenol and the upper layer of phenol dissolves in water.

Procedure:

• Weigh accurately 4 gm of phenol in a glass tube.

• Introduce glass rods and thermometer into it, fix the tube in a vertical position is a water bath setup the apparatus.

• Add 2ml of distilled water in a phenol and keep the test tube in a water bath whose 

temperature is initially raised to about 30 ̊C on low flame with constant stirring. Note the temperature (T1 ) of solution is obtained.

• Remove the tube from water bath and allow to cooling. It forms a turbid solution as 

temperature decreases. Note this temperature as (T2). That mean of T and T is the transition temperature (T).

• Add 2ml more of distilled water to a same tube and determine the transition temperature as in 

previous continue the addition of 2ml distilled water at the time to the same tube and record the transition temperature each time till the maximum transition. Temperature is reached and comes down to about 40 ̊ C.

percent by weight of phenol =        W1.   ×100

                                                           𝑊1 + 𝑊2

Weight of phenol (W1) =

Weight of water (W2) = 

Density of distilled water =

Density of phenol =

Water added = Vml

Result:

 critical solution temperature of phenol –water system at temperature_____℃ was found to be _____.