Question

250 mL of a solution with a solution with a Para-xylene a Concentration of 500 molL is placed in each of six containers with activated carbon and shaken for 24 hrs. The Samples are filtered, and the Concentration of P-Xylene measured, Yielding the following analyses: . z 4 Container 3 carbon, M(9) 24 16 P-xylene, co /13,7/ 16.6 27. mg/L 5 ४ 20 6 5 12 32 Plot the Freundlich isotherm & determine the Constants, K and n.

Answer 1

Freundlich Isothem

q_e = K_F (Ce)^1/n

$\Rightarrow$ ln q_e = ln K_F + (1/n) ln Ce

Y = C + mx

Where-

q_e - Equilibrium Adsorption Capacity (mg /g) = (Co - Ce) V/M

Ce - Equilibrium Concentration (mg/l)

K_F - Freundlich constant, representing adsorption capacity (mg/g)

Co - Initial Concentration

V - Volume of solution = 250 mL = 0.25 Lit

M - Mass of adsorbent (Here Activated Carbon)

Container	Co (mg/l)	Ce (mg/l)	m (gm)	qe (mg/g))	ln Ce	ln qe
1	500	13.7	24	5.065	2.617	1.622
2	500	16.6	20	6.042	2.809	1.798
3	500	27	16	7.390	3.295	2.00
4	500	32	12	9.750	3.465	2.277
5	500	49	8	14.093	3.891	2.645
6	500	110	5	19.50	4.70	2.970

Now plotting graph on excel

Chart Title 3.5 3 y = 0.668x -0.096 R2 = 0.969 2.5 N In qe s 1.5 Series1 Linear (Series1) 1 0.5 0 0 1 2 3 4 5 In Ce

From graph equation (Y = mx + C)

C = -0.096

$\Rightarrow$ ln K_F = - 0.096

$\Rightarrow$K_F = 0.908

Also,

m = 0.668

$\Rightarrow$ 1/n = 0.668

$\Rightarrow$ n = 1.497