Mass Transfer With Chemical Reaction

AIM: To find the mass transfer coefficient in a liquid-liquid system with and without chemical reaction.

PROCEDURE: The butyl acetate solution is saturated by mixing 50ml butyl acetate with 50ml water. The aqueous layer which settles out at the bottom is discharged 75ml of water is taken in a beaker and 10ml of saturated butyl acetate solution is added to it. The sitter is immersed in aqueous layer and stirred for 30 minutes. At any instant of time the interface should be visible. 10ml of aqueous sample is titrated with standard Na0H solution (0.05N). For conducting the experiment with chemical reaction, Na0H is used instead of water and stirring is done for 10 minutes. Titration is done with 0.05N Oxalic acid solution.

Butyl acetate + Water (Without chemical reaction)
Butyl acetate + Na0H (With reaction)

For without chemical reaction, KL is calculated using the equation,

(c* / (c*-c)) = KL at
t = time of stirring
a = interfacial area = area of contact/volume taken
KL = mass transfer coefficient
c* = equilibrium stability
For with reaction,
Ra = KLac*v
Where, v = volume taken, Ra = rate of mass transfer
Fall in normality = (C0-C)
C0=Concentration before stirring
C = Concentration after stirring
1. c* Vs normality of Na0H
2. KL Vs concentration of Na0H
Mass transfer coefficient without chemical reaction =
Mass transfer coefficient with chemical reaction =

1. Standardization of Na0H:
Normality of oxalic acid = Volume of Na0H run down =
Volume of oxalic acid taken = Normality of Na0H =

2. Area of contact:

Volume taken =
Interfacial area, a = Area of contact/Volume taken

3. Without Chemical Reaction:
Volume of sample taken =
Volume of Na0H run down =
Time of stirring, t =
Concentration, c* = 7.4 x 10 –5 g mol./cc.
(c*/c*-c)) = KL a t.
KL = ( 1 / at ) (c*/c* - c)

4. With chemical reaction:
Volume of Na0H taken, V =
Volume of sample taken =
Time stirring, t =
Normality of Oxalic acid = 0.05

S.No. Normality of Na0H Oxalic acid run down, ml
mol/cc. c x 106
mol/cc. Ra x 106
mol/sec. KL x 106



Fall in Normality, (c0-c) = Rate of mass transfer Ra = (c0-c) x v/t KL Ra = KL a c* v
KL= Ra / a c* v Conc. of Na0H