Conversions related to alkenes

Conversions related to alkenes:

                                          Following scheme will help you to solve many conversions and it is also easy to remember. These conversions start from alkenes and also end in alkenes.

The addition of HX obey Morkownikove’s rule:

                                Which states that Hydrogen  goes to that Carbon which have more Hydrogen in other word in an addition of unsymmetrical reagent to an unsymmetrical alkene,negative part of adding reagent goes to that carbon in a double bond which has least number of hydrogen atoms.

(This reaction is called ozonolysis and it is used to locate the the position of double bond in a alkene.In ozonolysis one should keep in mind that during the formation of product if the double bonded Carbon atom consist of Hydrogen atoms it will lead to aldehyde ,and if the Hydrogen is absent then it will lead to ketone .Symmetrical alkenes leads to symmetrical number of aldehyde or  ketone).

Organic conversions relating to alkanes

Conversions related to alkanes :

                        Most of the students find organic conversions difficult .For them here is a simple scheme of how can we carry out conversions.

Conversions which are directly or indirectly related to alkanes:

These conversions start from alkane and end at alkanes.

All coloured blocks are functional groups which you can be obtained following this scheme .

R-X=alkyle halides

R-OH=alcohal

R-CHO=aldehyde

R-COOH=carboxylic acid

R-NO₂=nitro alkane

R-MgX=alkyle magnesium halide(Grignard reagent)

For furthure querries post your question and conversions will be uploaded soon.

Difference between adsorption and absorption

Difference between adsorption and absorption:

Adsorption: 

• Chemical or physical adhesion of molecules or substances to the surface.
• It implies adhesion when liquid or gas stick to the surface of adsorbent with the preservation of their physical state.
• It is a surface phenomenon
• It is exothermic process.
• It occur at low Temperature ,at high T desorption occurs.
• Surface(adsorbent) is solid state  mostly on which the molecules attach.
• There is a relation ship between pores at the surface of adsorbent and size of adsorbate.
• It can be temporary or permanent .
• Mono and multilayer can form.
• It is not uniform always proceeding toward equilibrium
• Its rate  is not same,decreasing till attaining equilibrium.
• e.g Adhesion (Adsorption) of leach or mosquito to the human body surface. 
• Molecules (adsorbate) can be separated easily because of surface adhesion and lose attachment.

 Absorption:

• Distribution of molecules or substances(liquid or gas) through out the bulk.
• It implies assimilation and occurs through the conversion of gas into liquid,liquid into solid hence they may lost their physical state.
• It is a bulk phenomenon.
• It is endothermic process.
• Temprature does not affect.
• Molecules absorb in gas or liquid phase very easily.
• No effect of sizes of particles and no pores on surface as it is the bulk phenomenon.
• Absorption leads to permanent reaction.
• No formation of layers.
• It is uniform process of absorption throughout the bulk.
• Its rate remains same through the process.
• e.g when leach or mosquito absorbs or sucks blood from human body.
• Molecules can not be separated as they are assimilated in the matrix(bulk).

                                                                                                                                                                                                                                      

What is Desorption :

Desorption :

                             

Desorption is a process of releasing of sorbed (adsorption or absorption) substances.Removal of adsorb substances means removal of those substances which adhere to the surface and removal of absorbed molecule means removal of those  which were assimilated in the bulk (matrix or solution under consideration).

Desorption incoperates both adsorption and absorption phenomenon.Concentration of molecules is not  always same on the surface or in the bulk , but always wants to attain equilibrium .When this equilibrium is not attained or faces some disturbance due to some external factors (T,P) then desorption occurs.

As it is understood that molecules move from higher concentration to lower concentration,If the molecule concentration is lower in bulk ,then the molecules( adsorb or absorb) move into bulk in order to saturate.

 When the  surface molecules leaves they may converted into gas or liquid .It arises due to difference in bulk and surface concentration .If the binding between adsorbate and adsorbent is weak, subtances leave the surface in adsorption and  bulk in absorption ..e.g  when you peel out the cocumber and then smear it with salt ,water comes out of it these water molecules which were absorbed  before smearing salt and now they are desorped.

The surface molecules linked  to each other, when heated molecules transfer heat  fom one molecule to other,it will  leads  to desorption .Hence temprature when raised then thermal desorption occur.The reason behind is equilibrium is disturbed as some molecules evaporated due to heating (changed their phase) .Leaving behind a system which will incoperate molecules either absorbed or adsorbed to attain stable state.

Desorption is also the ability of a substance to move freely in the bulk.More it is mobile less its chances to adsorb.Hence conduction of heat is easier.

Preparation and composition of sago waste as an adsorbent:

Preparation and composition of Sago waste as an adsorbent:

                                                                          

                                                         

Sago palm(Cycus revoluta) a green leafy ornamental plant http://en.wikipedia.org/wiki/Cycas_revoluta .It is mostly cultivated  due to its beautiful long green leaves .If it is ingested by man it will be very dangerous some species of it are extremely poisonous.It propagates mostly through seeds.

 Sago waste as an adsorbent:

 In a present study, sago waste being used up as an adsorbent. It is a waste biomass, inexpensive and easily available. On the other hand it is granular and having the ability to remove the contamination from the waste water.Certain dyes are compatible and sago waste have prooved to remove many toxic metals  from effluents and inreturn toxicity free waste water is obtained .

  

Firstly twig off all the leaves and spread all the leaves onto the paper. Keep all the leaves on sun exposure, to set dry. Later the dried leaves grinded to obtain powder of raw leaves. Further passed such dried powder from the sieve in order to get more refine powder.in the long run introduced the powder into oven at low temprature  and let allow the powder moisture free. Now the adsorbent is ready to use.Pack the adsorbent in an air tight container. The composition of sago palm: Trunk weight varies from 800 kg to 1250 kg and pith weight varies from 643-850 kilograms. The pith contains 20.2 -29% starch and 50-66% water, the remainder being 13.8-21.3 per cent. Calculated on the basis of dry matter, the pith contains 54- 60% starch and 40-46% of other dry matter. The bark or cortex varies from 25.7% -32% of the trunk. Regarding sago, the granular starch size ranges from about 5-80 micro meters with an average of 30 microns. About 90% of the starch has a particle size of between 20-40 microns. Sago starch consists of 27% amylose and 73% amylopectin. Its gelatinization temperature is 700 centigrade.

       

Banana peel is compatible to adsorb methylene blue dye:

Banana peel is compatible to adsorb methylene blue dye:

Methylene blue is the heterocyclic compound with a chemical formula C₁₆H₁₈N₃SCl .It appear as a solid ,odorless,dark green colour powder .On dissolution it forms blue colour solution.Once you find out the compatible adsorbent for the adsorbate then further experiments are very easy .Banana peel have acompatibility to adsorb many toxic contaminants ,heavy metals and dyes .Banana peel is compatible to remove methylene blue.When industries using dyes like ethylene blue ,methylene blue ,bromophenol ,alizarin red,alizarin yellow etc ,to colour their products discharge waste water .This effluent is a greatest threat to the life nearby .Also this water is translocated and enters in the nearby land and causes many problems there.In order to over come the problem waste biomass adsorbents are nowadays very efficient . Banana peels are one of them. Banana peel can adsorb cadmium ,chromium http://www.sciencedirect.com/science/article/pii/S092777650800502X,platinium nano particles http://www.sciencedirect.com/science/article/pii/S0927776510002857 etc 

Sr. No.	Name of Dye	Molecular Formula	Structure Formula
1.	Methylene Blue	C16H18ClN3SCl

Compatibility test and steps for compatibility test for adsorbent to adsorb various dyes .

Compatibility test for adsorbent to adsorb various dyes .

                                     Compatibility test is the procedure through which we can find whether the given adsorbent can adsorb the adsorbate well or not.Compatibility testing is a method or a test which is employed to seek out the compatibility of the given solute with respect to its solvent. Basically it is the test encompasses the property of the solute and check out the reactivity with its solvent.If a solute has granular structure/porous body will be more compatible with its solvent.Adsorption is a efficient and low cost technique used for the purification of waste water which is responsible for the contamination of water.Many textile and other industries using various kinds of dyes e.g methylene blue,ethylene blue,bromophenol,alizarin red, alizarin yellow,methyl orange, methyl red and many many more .All these dyes have different compatibilities with low cost biomass adsorbents as banana peel ,sago waste,peanut shell, tea waste, husks etc.To get the efficient results first check the compatibility and then use adsorbent for purification of waste water.

Steps for compatibility test:

   For Compatibility testing steps are followings;

1.      Firstly prepare the stock solution of the dye (methylene blue/ ethylene blue) i.e., in a volumetric flask dissolved 1000mg of weighted amount of dye into 1000ml of distilled water to make 1000 ppm stock solution. From stock solution pippet out 10ml and added 90ml of water in it to make 100 ppm solution.

2.      Fixed the lambda max.λ_max (maximum wavelength) of the dye and determine the absorbance of the blank solution i.e., 100ppm through spectrophotometer(1100-visible).

3.       Passed the fixed amount of adsorbent dose i.e.,1g and let allow the solution to stand for an hour.

4.       After an hour maintained pH of the solution and filter out the solution.

5.        Now note down the after absorbance at the λ _max (maximum wavelength) of the dye.

6.         Compare the before and after absorbance of the solutions.

7.          After absorbance should be less than before absorbance. This is the key point of the compatibility testing.

8.         If the value of after absorbance less than before absorbance then adsorbent is compatible with dye. Lesser the after absorbance more compatible will be the adsorbent.

    Hence compatibility test is determined

Composition of banana peel .

Composition of banana peel.

                     

Banana peel is the outer covering of banana .Peels form 18-30%of the total fruit and are a waste product.Peels are good sources of cartenoids ,polyphenols and certain bio active compounds which impart beneficial effects on human health. On average banana peels contain 6-9% dry matter of protein and 20-30% fibre(measured as NDF).40% starch is found in green plantains .This starch get converted into sugars when they are fully riped. 30% free sugar  is found in ripe bananas and about 15%  starch.Leucine ,valine phenylalanine and threonine are essential amino acid present in considerable quantities .Lysine was the limiting amino acid .The content of lipid varies from 2-10% and was rich in polysaturated fatty acids ,particularly linoleic acid and alpha linoleic acid .Potassium is the most significant element.Starch is more in plantain peel than in banana peel. As the maturation proceeds ,increase in sugar content occur with the decrease in starch due to degradation of starch under the action of endogenous enzymes.

 .Chemical composition of banana peel is carbohydrate ,fiber,potassium ,maganese, iron,sodium. Traces of polyphenoles ,ether extractives and tannic acid is also present in banana depending upon which species of it is used.Many experiments have shown that banana peels have good antioxident potential and can be used for water purification ,for the removal of many toxic metals like copper,lead,cadmium ,chromium and nano particles etc.Banana peels have good compatility to adsorb dyes methylene blue ,ethylene blue and bromophenol before disposal in the water these dyes should be treated with compatible adsorbent to remove their toxicity.

Adsorbent prepared from waste banana peel(low cost )

Adsorbent prepared from waste banana peel .

                                       

 Banana peel waste can serve as a adsorbent ,this fruit waste is a environmental freindly adsorbent and can serve to remove many toxic contaminants from waste water. Banana peels are low cost.First banana peels are collected from your local areas .Banana peels are washed three times with tap water and three times with distilled water to remove external dirt. Dried and then cut in to smaller pieces.Peel waste are first dried in sunlight and at regular intervals in the oven at low temprature 105K  to get rid of remaining  moisture content.Then it is grounded into fine pwder and pass through the sieve  to get your desired size.If granules are there then again grind them and again pass them through sieve until finely powdered. Then save dried grinded,powdered  peels in air tight container .   

                             

Waste biomass is preferred over the commonly used adsorbents

Waste biomass is preferred over the commonly used adsorbent:

                         

Adsorption is one of several techniques which is very efficient due to its low cost ,easy handling and high efficiency to remove many organic and inorganic contaminants from waste water which industries using dyes as  to impart colour to their final products.This waste water can damage the water life by many ways as it can impart colour to their living water ,makes it unclear  and interferes with its intended beneficial used .

 How efficient is the adsorbent depends upon various factors .It includes particle size,chemical structure,pores size ,contact time ,surface area  ionization and solubility.For example silica gel ,activated carbon .Activated carbon is very efficient because it has a larger surface area and it is porous.It is  activated when heat is provided and oxygen is supplied .One gram of it  has a large surface area of five football fields [source: EPA].Silica gel is efficient enough to remove inorganic gases and also good for purification of gases.. The elements in biomass are commonly C, O, N, Ca, K, Si, Mg, Al, S, Fe, P, Cl, Na, Mn and Ti. There is a significant chemical distinction among the specified natural and anthropogenic biomass groups and sub-groups and they are related to different biomass sources and origin, namely from plant and animal products or from mixtures of plants, animal and manufacture materials.

Waste biomass:

                    It is mass which is obtained from living organisms or we can say biomass is the mass whose source is living  more likely plants or derived from plants,and is not living any more.As there are energy crisis all over the world and many developing countries suffering badly so they use biomass to fulfill their energy demands  .In a few decades the fossil energy sources like oil and coal we use nowadays will be exhausted. To avoid this we either must change our lifestyle and the habit of wasting energy or we have to find other ways to get energy without exploiting the earth.

In anyway

1.          Waste biomass is preferred over the commonly used adsorbent because waste biomass is very abundant. It can be found on every square meter of the earth as seaweed, trees or dung.
2.          It is also used for water purification.
3.          It is cheap in contrast to the other adsorbents.
4.         It has a wide usefulness and potential in enviromental conservation
5.         Adsorption science represents a viable and powerful tool,leading to the superior improvement of pollution control and environmental preservation
6.      Once you get a compatible waste biomass for specificdye,repeated experiments can be done for the removal of toxic metals to reach the higher level of accuracy 
7.     Waste biomass can easily prepared and handling is also very easy. 
8.    It is reproducible and renewable 
9.      The use of waste biomass is also eco-freindly as land fill disposal is reduced and space is available for more crops e.g felled trees ,wood waste,crops,paper waste, and aquatic plants .

             There are various dyes adsorbed on specific adsorbents this can be checked by testing dyes compatibility with the adsorbent.Various dyes got perfect compatibility and hence can easily removed from waste water .

Importance of dyes removal from aqueous solution

Importance of dyes removal from aqueous solution: 

                       

                                    

Every one loves to have such a beautiful scene but unfortunately  Industries using dyes to colour thier final product is very dangerous for the fresh and marine

water and inturn living organisms feeding on them get great threat .These dyes are very toxic .So before these

Why Adsorption is an exothermic process?

Adsorption is a exothermic reaction:

                             As we know adsorption is the interaction of adsorbate to adsorbent ,so there established a force of attraction between them ,which results in loss of heat .Hence it is exothermic process.Also decrease in residual forces causes decrease in surface energy of surface of adsorbent.

                                         G=H-TS

 According to above equation if the system is exothermic the value of G should be negative .As there is a gas adsorbed on the solid surface ,gas movement is constraint and hence decreasing its entropy i.e lacking of orderness.And for adsorption H is always negative so the process is exothermic.

Adsorption capacity and factors affecting it.

ADSORPTION CAPACITY:

               Adsorption capacity is the maximum amount of  solid surface to caught or hold in the solute particles or adsorbate.It can be shown as:
                                q_e = (C_i– C_e/ M)V
where q_{e is the amount adsorbed on the adsorbent ,M and V are the volume and mass of adsorbate .}C_{i and} C_{e is the concentration initial and at equilibrium.}

_{Factors affecting Adsorption capacity:}

       _{There are many factors that affect adsorption capacity these are:}

_{1.Size of adsorbate:}

        _{smaller size of particles is preferable .This is because equilibrium is more likely to achieved by smaller ,reduced and fine particles of adsorbate.If the adsorbate is of smaller size it can better be hold by the adsorbent.}

_{2.Contact time and surface area:}

        _{Adsorption needs time for completion more time given better will be the adsorption.Also the surface area should be large  for complete adsorption and it will lead adsorption to equilibrium position.}

Adsorption A brief and simple introduction

ADSORPTION:

The phenomena of attracting and retaining the molecules of a substance on the surface of a liquid or a solid resulting into a higher concentration of the molecules on the surface is called adsorption.In other words it is the phenomenon to collect molecules of solute on the top surface of solid or liquid . There is a electrostatic force build between solute and surface molecules because surface contains pores .Solute molecules incoperate in these pores. Solute particles or the molecules retained by the surface are called Adsobate and the surface on which these molecules adhere is called Adsorbent.

Adsorption is a different term than Absorption ,in which whole volume is involved i.e solute molecules penetrate in to the the matrix of solid or volume of liquid. The adsorption of gases on the surface of metals is called occlusion.Now the question is why adsorption is a surface phenomenon ,as adsorbent(Solid,liquid or gas)have some bonding sites which are occupied by neighboring atoms in the bulk.This pocess keeps on going until all the available bonding sites are occupied .But there are bonding site available on the surface also.So these surface bonding sites in order to achieve stability adsorb some external molecules (adsorbate).

Adsorbate when form first layer on the adsorbent it is known as monolayer .Multilayer adsorption occur when more then one layer is formed .Multilayer adsorption can be random or it can be non random depending upon conditions .The first layer which is formed is capable of good adhesion as compared to the multilayers formed after it(depends also on which type of forces present vander wal or covalent forces) .If weak forces exist between adsorbate and adsorbent vander wall forces this is known as Physiosorption and if strong forces say covalent bonding exists then it is known as Chemisorption .

Decolourization of water is the wonder of  adsorption.Adsorption is every where you can see it all around you.Almost everything is adsorbed on some kind of adsorbent.It can be seen in natural systems in physical ,biological ,chemical systems also .We are adsorbate also(Physical adsorption on the surface of earth. Hence adsorption is one of those phenomenon whse importance can not be denied in any sense.

Adsorption plays an important role in purification of indusrical waste water ,adsorbents adsorb many toxic metals and decolourized various dyes .These metals are cadmium ,chromium ,copper,maganese, zinc ,etc.  Many industries such as paper  ,textile ,cosmetics uses dyes to colour thier final product these dyes are highly dangerous and can cause serious hazardous problems .many techniques have been developed but adsorption prove to be most efficient and low cost.

Common adsorbents are activated carbon ,silica gel and alumina .But these adsorbents are of high cost .Studies have revealed that waste bio mass adsorbents are efficicient and low cost these are banana peel waste ,rice husk,tea waste ,coconut shells,egg shells,almound shells and many other fruit peels.  

  PROCESS OF ADSORPTION:

The process of adsorption arises due to presence of unbalanced or residual forces at the surface of liquid or solid phase. These unbalanced residual forces have tendency to attract and retain the molecular species with which it comes in contact with the surface. Adsorption is essentially a surface phenomenon.

Adsorption is a term which is completely different from Absorption .While absorption means uniform distribution of the substance throughout the bulk, adsorption essentially happens at the surface of the substance. When both Adsorption and Absorption processes take place simultaneously, the process is called sorption.

Adsorption process involves two components Adsorbent and Adsorbate. Adsorbent is the substance on the surface of which adsorption takes place.Adsorbate is the substance which is being adsorbed on the surface of adsorbent.

 TYPES OF ADSORPTION

Adsorption can be classified into two categories as described below:

(1) Depending upon the concentration :

 In adsorption the concentration of one substance is different at the surface of the other substance as compared to adjoining bulk or interior phase.

(i) Positive adsorption : 

If the concentration of adsorbate is more on the surface as compared to its concentration in the bulk phase then it is called positive adsorption.

Example of it is shaking of blood charcoal with concentrated solution of KCl .http://www.scribd.com/doc/87425689/Adsorption

(ii) Negative adsorption :

 When the concentration of adsorbate is more in bulk than its concentration on surface.Example of it is shaking of blood charcoal with dilute solution of KCl 

(2) Depending upon the nature of force existing between adsorbate molecule and adsorbent

(i) Physical adsorption :

 If the forces of attraction existing between adsorbate and adsorbent are Vander Waal’s forces, the adsorption is called physical adsorption. This type of adsorption is also known as physisorption or Vander Waal’s adsorption. It can be easily reversed by heating or decreasing the pressure.

(ii) Chemical adsorption :

If the forces of attraction existing between adsorbate particles and adsorbent are almost of the same strength as chemical bonds, the adsorption is called chemical adsorption. This type of adsorption is also called as chemisorption or Langmuir adsorption. This type of adsorption cannot be easily reversed.

 FACTORS WHICH AFFECT THE EXTENT OF ADSORPTION.                                                                            

The following are the factors which affect the adsorption:

(a) Nature of the adsorbate (gas) and adsorbent (solid)

(b) Surface area of the solid adsorbent

(c) Effect of pressure on the adsorbate gas

 (d) Effect of temperature

 Difference between Adsorption and Absorption:

ADSORPTION It is surface phenomenon i.e. it occurs only at the surface of the adsorbent. In this phenomenon, the concentration on the surface of adsorbent is different from that in the bulk. Its rate is high in the beginning and then decreases till equilibrium is attained.

ABSORPTION It is bulk phenomenon i.e. it occurs throughout the body of the material. In this phenomenon, the concentration is same throughout the material. Its rate remains same throughout the process.