Saturday, December 20, 2008

A Project Report On
“Adsorption of Oxalic Acid On Charcoal”
DECLARATION
I the undersigned, here by declare that the dissertation entitled “Study of Adsorption of Oxalic Acid on Charcoal”, written and submitted by me under the guidance of , Dept. of Chemistry , is one original Work.
ACKNOWLEDGEMENT

I am thankful to our chemistry lecturer Mr. for his constant encouragement during the process of this project and of course for his all kind of support and advices. I also would like to express my sincere thanks to my classmates, especially my group members for encouraging us and given all support for this project.
I take this opportunity to express my sincere and heartfelt gratitude to my respected principal
Mrs. for her permission to complete this project from .
Needless to say I have a vote of thanks to the guides for the support rendered in the course of my task, especially , Chemistry Lab Asst. for the completion of this project.
I thank the almighty GOD without whose blessing this project would remain still a dream. The joy and satisfaction that accompany the successful completion of any task would be incomplete without the mention of those who made it possible.
CONTENTS

1. Introduction
2. Objectives
3. Apparatus
4. Theory
5. Procedure
6. Observation
7. Result and Discussion
8. Conclusion
INTRODUCTION

ADSORPTION
The situation existing at the surface of a liquid or solid is different from that in the interior. Inthe interior of the liquid or solid molecules experience attraction on all sides, where as molecules on the surface have other neighboring molecules only below and on the sides. As a result surface molecules experiences a net attraction downwards and there are residual forces on the molecules at the surface in the solids the residual forces are also due to the presence of unsatisfied valance forces of atom at the surface. The unsatisfied vacancies arise when some of the inter atomic bonds are broken, during the average of bigger crystals into smaller fragments. As a result these unbalanced residual force, the surface of a liquid or solid is said to be in a state of strain or unsaturation.to satisfy the residual forces, particles of gases and liquids around are attracted to the surface, there by creating an excess concentration at the surface.

TYPES OF ADSORPTION
there are mainly two types of adsorption gases on solids if the accumulation of gas on the surface of a solid occur on account of week Vander Wals force the adsorption is termed as the physical adsorption or physisorption. When the gas molecules or atoms are held to the solid surface by chemical bonds, the adsorption is termed as the chemical adsorption or chemisorption. The chemical bond may be covalent or ionic in nature. it involve a high energy of activation and is there some, often reserved to as activated adsorption. Some times these two process occur simultaneously and it is not easy to a certain type of adsorption.a physical adsorption at low temp may pass into chemisorption as the temperature increased.

ADSORPTION FROM SOLUTION PHASE
Solids can adsorb solutes from solutions. When a solution of acetic acid in water is shaken with charcoal part of the acid adsorbed by the charcoal and the concentration of the charcoal becomes colourless. The precipitate of Mg(OH)2 attains blue color when the precipitation take place in the presents of maganazone reagent. The following observations are made in the case of adsorption from solution base.
1) The extend of adsorption decrease with an increase in temperature
2) The extend of adsorption increases with an increase of surface area of adsorbent.
3) The extend of adsorption depends upon the concentration of solutes present in the solution.
5) The extend of adsorption depend on the nature of adsorbent and the adsorbate.

OBJECTIVES
1. To find out the extend of adsorption of oxalic acid on charcoal.
2. To check whether it fits to Langmuir Adsorption Isotherm.
3. To find out whether the extend of adsorption is maximum from dilute solution or concentrated solution.
APPARATUS
· Five Glass Bottles with appropriate labels
· Common Balance
· Beaker
· Measuring Cylinder
· Funnel
· Conical Flask
· Glass Rod
· Filter Paper
· Burette
· Pipette
· Water bath


CHEMICALS USED

· Coconut Shell Charcoal
· Oxalic Acid
· NaOH
· Water
· Phenolphthalein


PROCEDURE

For our project entitled as adsorption of oxalic acid on charcoal we followed a step by step procedure. At first we collected many data for it from many books and internet, to study more about the topic. In the second stage we started conducting experiment under the guidance of our respected chemistry teacher Mr.Nasimuddin.
We made finely divided coconut charcoal. We washed 5 glass bottles cleanly with water and made them dry. Then 2g of charcoal is weighed five times into each of the glass bottles. Room temperature is noted. The oxalic acid solution of concentrations 0.1, 0.08, 0.06, 0.04, 0.02 respectively is added to each of the glass bottles. These bottles are shaken for 20 minute in a water bath. Then the solution from each bottle is filtered, and 20ml of filtered solution from each bottle are titrated against NaOH solution. Then Langmuir Adsorption Isotherm is plotted by plotting Ce/(x/m) against Ce. The Longmuir’s parameters are determined.
Amount initial vol vol of eqbm conce(Ce) X=(ci-ce)50 X/m Ce/(x/m)
of conce titrate(ml) NaOH(ml) xEq.mass of
charcoal (ci) acid/1000
2g 0.1 20
2g .02 20
2g .04 20
2g .08 20
RESULT AND DISCUSSION


· Different extends of adsorption is observed for different concentrations of Oxalic acid.
· The readings got fit to Langmuir Adsorption Isotherm.
· The extend of adsorption is maximum for maximum concentration of oxalic acid.
· The extend of adsorption is minimum for minimum concentration of oxalic acid.
· This can be extended to other organic acids too.
CONCLUSION

· The extend of adsorption of oxalic acid on charcoal for different concentrations are found.
· The extend of adsorption are found fit to Langmuir Adsorption Isotherm.
· Extend of adsorption is maximum from maximum concentrated solution of oxalic acid.

Tuesday, December 2, 2008

ADAPTATIONS IN HYDROPHYTES AND XEROPHYTES

Hydrophytes (Adaptations in plants to aquatic environment)
The plants which are growing in water partially or completely are known as aquatic plants or hydrophytes. Water may be freshwater or saline. Plants which grow in fresh water bodies like ponds, lakes, pools, streams, rivers etc.are known as freshwater plants, and those growing in salt water are known as saltwater plants or marine plants. The free-floating, on-vascular hydrophytes constitute phytoplanktons.
The aquatic plants show the following adaptations.
Morphological adaptations
1. Roots may completely be lacking (wolffia, utricularia) or feebly developed (hydrilla).
2. Root hairs are absent (lemna) or feebly developed.
3. Roots caps may be absent or root pockets are present (eichornia).
4. Roots are generally fibrous type and adventitious, unbranched or sparsely branched.
5. The stem is long, slender, weak, spongy and flexible type in submerged hydrophytes.
6. The stem is short, stoloniferous, thick, and spongy, with extensive parenchyma in free floating plants.
7. The leaves may arrange in alternate phyllotaxy (potamogeton) or opposite (cabwoman) or whorled (hydrilla).
8. Stomata are present on the upper epidermis which is in contact with air and gaseous exchange takes place through this stomata and lower surface is in touch with water.
9. The upper leaf surface in floating leaves are coated with wax to prevent wilting.
10. The of many partially submerged plants show hetrophylly (presence of different types of leaves).
E.g. ranunculus aquatilis
11. The entire plant body covered with mucilage.
12. The flowers and seeds are less abundant.
13. Reproduction is mainly by vegetative methods.
Anatomical adaptations
1. Excessive development of parenchyma and elaborate system of arenchyma (air space)
2. Poor development of vascular and mechanical tissues.
3. Cuticle absent or poorly developed
4. Stomata are completely absent in submerged leaves.]
5. Chlorophyll found in all the tissues.
6. Mucilage canals and mucilage cells are present which secrete mucilage to protect the plant body.
7. The reserve food is in the form of starch grains which occur in cortex and pith.
8. Cystoliths (sclereids) of various shapes are seen in leaves and other tissues.
Xerophytes (Adaptations to dry environment)

The plants which are growing in xeric (dry) environment (habitat) are called Xerophytes. Deserts are the best examples for xeric environment, where plant face inadequate water and excessive transpiration .xerophytes are classified into the following three categories-Ephemerals [the plants complete their life cycle within a short period. they also called “drought escapers” or “drought evaders”], Succulents [these plants have succulent, fleshy organs, to store to store high amount of water accumulated during rainy seasons. these xerophytes suffer dryness only in external environment],true xerophytes[these plants which are able to live under extreme dry conditions and high temperature].the xerophytes show the following adaptations.
Morphological adaptations
1. Stem shows stunted growth
2. Certain plants have under ground stem to tide over dry season.
3. Plants like acacia, zizyphus etc .have very hard ,woody stem with thick bark.
4. In many plants the leaves are reduced to scaly or spiny e.g.ruscus, asparagus etc.
5. Many plants have very small and narrow leaf blade to reduce the transpiration area.
6. Some plants have shining leaf surface to reflect light. E.g.nerium odorum.
7. In certain plant leaves leaves are very thick and leathery to reduce transpiration. E.g.calotropis procera
8. Many plants have waxy coating on the upper surface of leaves.
9. Folded type leaves are seen in some of the grasses to protect the
10. In non-succulent plants root system is several times larger than the aerial portion.
Anatomical adaptations
1. Presence of thick cuticle on the upper surface of leaves.
2. The epidermal cells are thick walled.
3. Multiple epidermal layers are seen on both upper and lower surface of leaves.
4. Stomata are reduced in numbers and are sunken type.
5. The stomata pits are filled with number of hairs.
6. Thick walled sclerenchyma cells are seen in the hypodermis. E.g. pinus needle
7. Few spongy parenchyma cells with small inter cellular spaces.
8. Presence of many layered palisade parenchyma
9. The cells are relatively smaller in size and vacuoles are small.
10. Well developed vascular tissues are present.
Materials and methods
Materials:-
Xerophytes root, stem.
Hydrophytes stem, leaf, and root
Methods:-
Take the transverse of the stem and root mounded with glycerin after
Mounded with glycerin after the stained.
Observed prepared slide through microscope.