Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
purification of organic compound
Transcript of purification of organic compound
Purification the physical separation of a chemical substance of interest from foreign or contaminating substances
List of purification methods in chemistry
Affinity purification .
purificationof organic compound
useful technique for dissolving out a component from a mixture using a suitable solvent Assume we wish to extract iodine which is dissolved in water together with some impurities
USING A SEPARATING FUNNEL
Immiscible liquids,such as oil and water can be separated by using a separating funnel. The mixture is put into a separating funnel, shaken and allowed to settle
To separate a solid compound in pure and geometrical form.
A saturated solution of the impure substance in a suitable solvent is made at a temperature higher than the room temperature. On cooling this solution, the substance reappears in the form of well shaped crystals.
Purification by crystallization involves the following steps:
Choice of solvent
Preparation of solution
Filtration of the solution
Separating the crystals
Drying of crystals
Crystallisation of Phthalic acid
To separate volatile solids, which pass directly into vapour state on heating from a non-volatile solid.
A mixture of solid substances, such as camphor, benzoic acid, ammonium chloride, iodine etc., containing non-volatile substances, when heated, change directly into vapour without passing through the liquid state
To separate a solution of a solid in a liquid and for separating a solution of two liquids whose boiling points are different.
Distillation involves the conversion of a liquid into its vapors upon heating and then cooling the vapors back into the liquid. Depending on the difference in boiling points of liquids.
Types of distillation
Distillation Under Reduced Pressure or Vacuum Distillation
It is used for separating liquids having boiling points differing by 10-20 degrees. The liquid having the lower boiling point distills over first, and the other liquid component is left behind. In this process , vaporization and condensation occur side by side.
Simple distillation of a Cyclohexane- Toluene mixtures
It is used for separating two liquids in any mixture, which have boiling points within a narrow range of temperatures.
In such cases, simple distillation does not give complete separation and a modified version called fractional distillation is employed.
Fractional Distillation of a Cyclohexane- Toluene
This technique is used for separating/purifying liquids,which are immiscible with water, volatile in steam, & have high vapor pressure at the boiling temperature of water.
Isolation of Citral
To identify, purify and/or separate constituents of a mixture
that are present in very small amounts.
The principle behind this technique is the differential
adsorption of the various components of a mixture between two different phases that are as follows:
Fixed or stationary phase
Mobile or Moving phase
COMMONLY EMPLOYED CHROMATOGRAPHIC TECHNIQUES
*Ascending and Descending Paper *Chromatography
*Radial Paper Chromatography
*Thin Layer Chromatography
THIN LAYER CHROMATOGRAPHY
In this chromatography, the stationary phase is a thin
layer of an adsorbent (generally alumina) coated on
Flat glass strip. The solvent (mobile phase) moves up
the layer due to the capillary action and thus causes
the separation of constituents of the mixture.
The constituents are identified by measuring their
Separation of vitamins by thin layer chromatography
To extract a compound that is present in very small amounts in an aqueous solution with the help of an organic liquid in which that compound is highly soluble
The systematic qualitative analysis of organic
compounds includes the following different stages:
*Preliminary tests and physical examinations.
*Detection of elements
*Determination of functional group or groups.
*Determination of physical constant.
*Identification of the compound by search of literature with similar physical and chemical properties.
*Confirmation of compounds by preparing suitable derivative and specific chemical tests.
1. Arthur .I. Vogel, “Elementary Practical Organic
Chemistry” part -1st CBS Publication second edition 2004,
2. Arun Bahl, B.S. Bahl,” Organic chemistry “S.Chand, 16th
edition 2004, page no -375.
3. B. S. Furniss, A.J .Hannoford, P W G Smith, A.R.Tatchell
“Vogel Practical Organic chemistry”, published by
Pearson education, 5th edition, page no -131-210.
4. L.f. fieser , K. L. Williamson “ Organic Experiment “
published by CBS 7th edition page no 27,69,71-99.
Example :-Extraction of Caffeine from Tea