Physical Principles II

CEBU CITY

Chemical Engineering Department

Name: Juphil A. Lamanilao Date: October 15, 2009

Course & Yr: BSChE-4

I.TITLE: Adsorption from Solutions of Acetic Acid on Charcoal

II.OBJECTIVE:

To determine the K and N of the Freundlich adsorption isotherm.

III.APPARATUS:

25 ml Burette, 100 ml calibrated flask, (2) small long-stemmed funnels, 9cm filter paper, about 20g of active charcoal, 250ml of 0.50M CH3COOH, 150 ml of std. standard 0.10M NaOH

IV.SKETCH:

Adsorption from Solutions Acetic Acid on Charcoal 1

Physical Principles II

V.TABULATED DATA & RESULTS:

SOLUTION(++ 100ml H2O)

SOLUTION USED (ml)

NaOH USED (ml)

Filtrate A 50 1.5Filtrate B 50 1.1Filtrate C 50 1.6Filtrate D 50 1.5Filtrate E 50 1.5Filtrate F 50 1.2

VI.SAMPLE COMPUTATIONS:

For Carbon: A. K= 2÷0.50.17=2.25m=2g B. K=

2÷0.250.17=2.53 n=m÷atomic wt.= 2g÷12g/molC. K= 2÷0.1250.17=2.85 =0.17

mol D. K= 2÷0.06250.17=3.20 m=KCn; K=m÷Cn

E. K= 2÷0.031250.17=3.61F. K= 2÷0.01560.17=4.01

Adsorption from Solutions Acetic Acid on Charcoal 2

SOLUTION(+ 100ml HAc)

SOLUTION USED (ml)

NaOH USED (ml)

A. 2g C (0.5M HAc) 5 86B. 2g C (0.25M HAc) 10 70.4C. 2g C (0.125M HAc) 25 54D. 2g C (0.0625M HAc) 50 51E. 2g C (0.03125M HAc) 50 44.2F. 2g C (0.0156M HAc) 50 13

Physical Principles II

VII. DATA ANALYSIS:

Solid surfaces can adsorb dissolved substances from solution. When a solution of acetic acid in water is shaken with activated carbon, part of the acid is removed by the carbon and the concentration of the solution decreased. From the results gathered, it is realized that K increases as the concentration of CH3COOH is decreased with respect to time. Hence, the degree to which a solid will adsorb material depends on a number of things including temperature, nature of molecule being adsorbed, degree of surface pore structure, and, solute concentration & solvent. Other factors are important factors dealing with the process of adsorption of solutes from aqueous solution by highly porous solids.

VIII.APPLICATION TO ChE:

Adsorption finds very extensive application both in the research laboratory and in industry. It plays a very important part in various aspects of catalysis of gaseous reaction by solid surfaces. In similar manner, various adsorbents are used in industry to recover solvent vapors from air, or particular solvents from mixture of the other gases. It has been used through chromatographic analysis for the recovery and concentration of vitamins and other biologic substances. As application of adsorption from solutions may involved the clarification of sugar of sugar liquors by charcoal, the removal of coloring matter from various other types of solutions and the recovery of dies from dilute solutions in a number of solvents

IX.CONCLUSION:

Adsorption from solution follows generally the principles laid down for the adsorption of gases. Variation of extend of adsorption with concentration of solute is usually represented by the Freundlich isotherm and the Langmuir isotherm. A boundary that separates two phases is known as a surface or an interface. Surfaces show special properties that are different from those of the phases themselves. This is an example of physical adsorption, where dipole and van der Waals forces are the predominant sources of attraction. For example, the surface of a solid often shows a strong affinity for molecules that come into contact with it and which are said to be adsorbed. The amount of acetic acid (adsorbate) adsorbed per gram of charcoal (adsorbent) will depend on the surface area of the charcoal, the temperature of the solution and the absorbate concentration in solution. The adsorption is

Adsorption from Solutions Acetic Acid on Charcoal 3

Physical Principles II

followed by titrating the acetic acid not absorbed by the charcoal and then the amount absorbed by difference is determined.

Adsorption from Solutions Acetic Acid on Charcoal 4